The bare recital of the Bronte story can give no idea of its undying interest, its exceeding pathos. Their life as told by their biographer Mrs Gaskell is as interesting as any novel. Their achievement, however, will stand on its own merits. Anne Bronte's two novels, it is true, though constantly reprinted, survive principally through the exceeding vitality of the Bronte tradition. As a hymn writer she still has a place in most religious communities. Emily is great alike as a novelist and as a poet. Her "Old Stoic" and "Last Lines" are probably the finest achievement of poetry that any woman has given to English literature. Her novel Wuthering Heights stands alone as a monument of intensity owing nothing to tradition, nothing to the achievement of earlier writers. It was a thing apart, passionate, unforgettable, haunting in its grimness, its grey melancholy. Among women writers Emily Bronte has a sure and certain place for all time. As a poet or maker of verse Charlotte Bronte is undistinguished, but there are passages of pure poetry of great magnificence in her four novels, and particularly in Villette. The novels Jane Eyre and Villette will always command attention whatever the future of English fiction, by virtue of their intensity, their independence, their rough individuality.

The Life of Charlotte Bronte, by Mrs Gaskell, was first published in 1857. Owing to the many controversial questions it aroused, as to the identity of Lowood in Jane Eyre with Cowan Bridge school, as to the relations of Branwell Bronte with his employer's wife, as to the supposed peculiarities of Mr Bronte, and certain other minor points, the third edition was considerably changed. The Life has been many times reprinted, but may be read in its most satisfactory form in the Haworth edition (1902), issued by the original publishers, Smith, Elder & Co. To this edition are attached a great number of letters written by Miss Bronte to her publisher, George Smith. The first new material supplied to supplement Mrs Gaskell's Life was contained in Charlotte Bronte: a Monograph, by T. Wemyss Reid (1877). This book inspired Mr A.C. Swinburne to issue separately a forcible essay on Charlotte and Emily Bronte, under the title of A Note on Charlotte Bronte (1877). A further collection of letters written by Miss Bronte was contained in Charlotte Bronte and her Circle, by Clement Shorter (1896), and interesting details can be gathered from the Life of Charlotte Bronte, by Augustine Birrell (1887), The Brontes in Ireland, by William Wright, D.D. (1893), Charlotte Bronte and her Sisters, by Clement Shorter (1906), and the Bronte Society publications, edited by Butler Wood (1895-1907). Miss A. Mary F. Robinson (Madame Duclaux) wrote a separate biography of Emily Bronte in 1883, and an essay in her Grands Ecrivains d'outre-Manche. The Brontes: Life and Letters, by Clement Shorter (1907), contains the whole of C. Bronte's letters in chronological order.

(C. K. S.)

BRONTE, a town of the province of Catania, Sicily, on the western slopes of Mt. Etna, 24 m. N.N.W. of Catania direct, and 34 m. by rail. Pop. (1901) 20,366. It was founded by the emperor Charles V. The town, with an extensive estate which originally belonged to the monastery of Maniacium (Maniace), was granted, as a dukedom, to Nelson by Ferdinand IV. of Naples in 1799.

BRONX, THE, formerly a district comprising several towns in Westchester county, New York, U.S.A., now (since 1898) the northernmost of the five boroughs of New York City (q.v.). Several settlements in the Bronx were made by the English and the Dutch between 1640 and 1650.

BRONZE, an alloy formed wholly or chiefly of copper and tin in variable proportions. The word has been etymologically connected with the same root as appears in "brown," but according to M.P.E. Berthelot (La Chimie au moyen age) it is a place-name derived from aes Brundusianum (cf. Pliny, Nat. Hist. xxxiii. ch. ix. Sec.45, "specula optima apud majores fuerunt Brundusiana, stanno et aere mixtis"). A Greek MS. of about the 11th century in the library of St Mark's, Venice, contains [v.04 p.0640] the form [Greek: brontesion], and gives the composition of the alloy as 1 lb of copper with 2 oz. of tin. The product obtained by adding tin to copper is more fusible than copper and thus better suited for casting; it is also harder and less malleable. A soft bronze or gun-metal is formed with 16 parts of copper to 1 of tin, and a harder gun-metal, such as was used for bronze ordnance, when the proportion of tin is about doubled. The steel bronze of Colonel Franz Uchatius (1811-1881) consisted of copper alloyed with 8% of tin, the tenacity and hardness being increased by cold-rolling. Bronze containing about 7 parts of copper to 1 of tin is hard, brittle and sonorous, and can be tempered to take a fine edge. Bell-metal varies considerably in composition, from about 3 to 5 parts of copper to 1 of tin. In speculum metal there are 2 to 21/2 parts of copper to 1 of tin. Statuary bronze may contain from 80 to 90% of copper, the residue being tin, or tin with zinc and lead in various proportions. The bronze used for the British and French copper coinage consists of 95% copper, 4% tin and 1% zinc. Many copper-tin alloys employed for machinery-bearings contain a small proportion of zinc, which gives increased hardness. "Anti-friction metals," also used in bearings, are copper-tin alloys in which the amount of copper is small and there is antimony in addition. Of this class an example is "Babbitt's metal," invented by Isaac Babbitt (1799-1862); it originally consisted of 24 parts of tin, 8 parts of antimony and 4 parts of copper, but in later compositions for the same purpose the proportion of tin is often considerably higher. Bronze is improved in quality and strength when fluxed with phosphorus. Alloys prepared in this way, and known as phosphor bronze, may contain only about 1% of phosphorus in the ingot, reduced to a mere trace after casting, but their value is nevertheless enhanced for purposes in which a hard strong metal is required, as for pump plungers, valves, the bushes of bearings, &c. Bronze again is improved by the presence of manganese in small quantity, and various grades of manganese bronze, in some of which there is little or no tin but a considerable percentage of zinc, are extensively used in mechanical engineering. Alloys of copper with aluminium, though often nearly or completely destitute of tin, are known as aluminium bronze, and are valuable for their strength and the resistance they offer to corrosion. By the addition of a small quantity of silicon the tensile strength of copper is much increased; a sample of such silicon bronze, used for telegraph wires, on analysis was found to consist of 99.94% of copper, 0.03% of tin, and traces of iron and silicon.

The bronze (Gr. [Greek: chalkos], Lat. aes) of classical antiquity consisted chiefly of copper, alloyed with one or more of the metals, zinc, tin, lead and silver, in proportions that varied as times changed, or according to the purposes for which the alloy was required. Among bronze remains the copper is found to vary from 67 to 95%. From the analysis of coins it appears that for their bronze coins the Greeks adhered to an alloy of copper and tin till 400 B.C., after which time they used also lead with increasing frequency. Silver is rare in their bronze coins. The Romans also used lead as an alloy in their bronze coins, but gradually reduced the quantity, and under Caligula, Nero, Vespasian and Domitian, coined pure copper coins; afterwards they reverted to the mixture of lead. So far the words [Greek: chalkos] and aes may be translated as bronze. Originally, no doubt, [Greek: chalkos] was the name for pure copper. It is so employed by Homer, who calls it [Greek: eruthros] (red), [Greek: aithups] (glittering), [Greek: phaennos] (shining), terms which apply only to copper. But instead of its following from this that the process of alloying copper with other metals was not practised in the time of the poet, or was unknown to him, the contrary would seem to be the case from the passage (Iliad xviii. 474) where he describes Hephaestus as throwing into his furnace copper, tin, silver and gold to make the shield of Achilles, so that it is not always possible to know whether when he uses the word [Greek: chalkos] he means copper pure or alloyed. Still more difficult is it to make this distinction when we read of the mythical Dactyls of Ida in Crete or the Telchines or Cyclopes being acquainted with the smelting of [Greek: chalkos]. It is not, however, likely that later Greek writers, who knew bronze in its true sense, and called it [Greek: chalkos], would have employed this word without qualification for objects which they had seen unless they had meant it to be taken as bronze. When Pausanias (iii. 17. 6) speaks of a statue, one of the oldest figures he had seen of this material, made of separate pieces fastened together with nails, we understand him to mean literally bronze, the more readily since there exist very early figures and utensils of bronze so made.

For the use of bronze in art, see METAL-WORK.

BRONZE AGE, the name given by archaeologists to that stage in human culture, intermediate between the Stone and Iron Ages, when weapons, utensils and implements were, as a general rule, made of bronze. The term has no absolute chronological value, but marks a period of civilization through which it is believed that most races passed at one time or another. The "finds" of stone and bronze, of bronze and iron, and even of stone and iron implements together in tumuli and sepulchral mounds, suggest that in many countries the three stages in man's progress overlapped. From the similarity of types of weapons and implements of the period found throughout Europe a relatively synchronous commencement has been inferred for the Bronze Age in Europe, fixed by most authorities at between 2000 B.C. to 1800 B.C. But it must have been earlier in some countries, and is certainly known to have been later in others; while the Mexicans and Peruvians were still in their bronze age in recent times. Not a few archaeologists have denied that there ever was a distinct Bronze Age. They have found their chief argument in the fact that weapons of these ages have been found side by side in prehistoric burial-places. But when it is admitted that the ages must have overlapped, it is fairly easy to undertand the mixed "finds." The beginning, the prevalence and duration of the Bronze Age in each country would have been ordered by the accessibility of the metals which form the alloy. Thus in some lands bronze may have continued to be a substance of extreme value until the Iron Age was reached, and in tumuli in which more than one body was interred, as was frequently the case, it would only be with the remains of the richer tenants of the tomb that the more valuable objects would be placed. There is, moreover, much reason to believe that sepulchral mounds were opened from age to age and fresh interments made, and in such a practice would be found a simple explanation of the mixing of implements. Another curious fact has been seized on by those who argue against the existence of a Bronze Age. Among all the "finds" examined in Europe there is a most remarkable absence of copper implements. The sources of tin in Europe are practically restricted to Cornwall and Saxony. How then are we to explain on the one hand the apparent stride made by primitive man when from a Stone Age civilization he passed to a comparatively advanced metallurgical skill? On the other, how account for a comparatively synchronous commencement of bronze civilization when one at least of the metals needed for the alloy would have been naturally difficult of access, if not unknown to many races? The answer is that there can be but little doubt that the knowledge of bronze came to the races of Europe from outside. Either by the Phoenicians or by the Greeks metallurgy was taught to men who no sooner recognized the nature and malleable properties of copper than they learnt that by application of heat a substance could be manufactured with tin far better suited to their purposes. Copper would thus have been but seldom used unalloyed; and the relatively synchronous appearance of bronze in Europe, and the scanty "finds" of copper implements, are explained. We may conclude then that there was a Bronze Age in most countries; that it was the direct result of increasing intercommunication of races and the spread of commerce; and that the discovery of metals was due to information brought to Stone-Age man in Europe by races which were already skilful metallurgists.

The Bronze Age in Europe is characterized by weapons, utensils and implements, distinct in design and size from those in use in the preceding or succeeding stage of man's civilization. Moreover—and this has been employed as an argument in favour of the foreign origin of the knowledge of bronze—all the [v.04 p.0641] objects in one part of Europe are identical in pattern and size with those found in another part. The implements of the Bronze Age include swords, awls, knives, gouges, hammers, daggers and arrow-heads. A remarkable confirmation of the theory that the Bronze Age culture came from the East is to be found in the patterns of the arms, which are distinctly oriental; while the handles of swords and daggers are so narrow and short as to make it unlikely that they would be made for use by the large-handed races of Europe. The Bronze Age is also characterized by the fact that cremation was the mode of disposal of the dead, whereas in the Stone Age burial was the rule. Barrows and sepulchral mounds strictly of the Bronze Age are smaller and less imposing than those of the Stone Age. Besides varied and beautiful weapons, frequently exhibiting high workmanship, amulets, coronets, diadems of solid gold, and vases of elegant form and ornamentation in gold and bronze are found in the barrows. These latter appear to have been used as tribal or family cemeteries. In Denmark as many as seventy deposits of burnt bones have been found in a single mound, indicating its use through a long succession of years. The ornamentation of the period is as a rule confined to spirals, bosses and concentric circles. What is remarkable is that the swords not only show the design of the cross in the shape of the handle, but also in tracery what is believed to be an imitation of the Svastika, that ancient Aryan symbol which was probably the first to be made with a definite intention and a consecutive meaning. The pottery is all "hand-made," and the bulk of the objects excavated are cinerary urns, usually found full of burnt bones. These vary from 12 to 18 in. in height. Their decoration is confined to a band round the upper part of the pot, or often only a projecting flange lapped round the whole rim. A few have small handles, formed of pierced knobs of clay and sometimes projecting rolls of clay, looped, as it were, all round the urn. The ornamentation consists of dots, zigzags, chevrons or crosses. The lines were frequently made by pressing a twisted thong of skin against the moist clay; the patterns in all cases being stamped into the pot before it was hardened by fire.

See ARCHAEOLOGY, &c. Also Lord Avebury, Prehistoric Times (1900); Sir J. Evans, Ancient Bronze Implements of Great Britain (1881); Chartre's Age du bronze en France.

BRONZING, a process by which a bronze-like surface is imparted to objects of metal, plaster, wood, &c. On metals a green bronze colour is sometimes produced by the action of such substances as vinegar, dilute nitric acid and sal-ammoniac. An antique appearance may be given to new bronze articles by brushing over the clean bright metal with a solution of sal-ammoniac and salt of sorrel in vinegar, and rubbing the surface dry, the operation being repeated as often as necessary. Another solution for the same purpose is made with sal-ammoniac, cream of tartar, common salt and silver nitrate. With a solution of platinic chloride almost any colour can be produced on copper, iron, brass or new bronze, according to the dilution and the number of applications. Articles of plaster and wood may be bronzed by coating them with size and then covering them with a bronze powder, such as Dutch metal, beaten into fine leaves and powdered. The bronzing of gun-barrels may be effected by the use of a strong solution of antimony trichloride.

BRONZINO, IL, the name given to ANGELO ALLORI (1502-1572), the Florentine painter. He became the favourite pupil of J. da Pontormo. He painted the portraits of some of the most famous men of his day, such as Dante, Petrarch and Boccaccio. Most of his best works are in Florence, but examples are in the National Gallery, London, and elsewhere.

BRONZITE, a member of the pyroxene group of minerals, belonging with enstatite and hypersthene to the orthorhombic series of the group. Rather than a distinct species, it is really a ferriferous variety of enstatite, which owing to partial alteration has acquired a bronze-like sub-metallic lustre on the cleavage surfaces. Enstatite is magnesium metasilicate, MgSiO3, with the magnesia partly replaced by small amounts (up to about 5%) of ferrous oxide; in the bronzite variety, (Mg,Fe)SiO3, the ferrous oxide ranges from about 5 to 14%, and with still more iron there is a passage to hypersthene. The ferriferous varieties are liable to a particular kind of alteration, known as "schillerization," which results in the separation of the iron as very fine films of oxide and hydroxides along the cleavage cracks of the mineral. The cleavage surfaces therefore exhibit a metallic sheen or "schiller," which is even more pronounced in hypersthene than in bronzite. The colour of bronzite is green or brown; its specific gravity is about 3.2-3.3, varying with the amount of iron present. Like enstatite, bronzite is a constituent of many basic igneous rocks, such as norites, gabbros, and especially peridotites, and of the serpentines which have been derived from them. It also occurs in some crystalline schists.

Bronzite is sometimes cut and polished, usually in convex forms, for small ornamental objects, but its use for this purpose is less extensive than that of hypersthene. It often has a more or less distinct fibrous structure, and when this is pronounced the sheen has a certain resemblance to that of cat's-eye. Masses sufficiently large for cutting are found in the norite of the Kupferberg in the Fichtelgebirge, and in the serpentine of Kraubat near Leoben in Styria. In this connexion mention may be made of an altered form of enstatite or bronzite known as bastite or schiller-spar. Here, in addition to schillerization, the original enstatite has been altered by hydration and the product has approximately the composition of serpentine. In colour bastite is brown or green with the same metallic sheen as bronzite. The typical locality is Baste in the Radauthal, Harz, where patches of pale greyish-green bastite are embedded in a darker-coloured serpentine. This rock when cut and polished makes an effective decorative stone, although little used for that purpose.

(L. J. S.)

BROOCH, or BROACH (from the Fr. broche, originally an awl or bodkin; a spit is sometimes called a broach, and hence the phrase "to broach a barrel"; see BROKER), a term now used to denote a clasp or fastener for the dress, provided with a pin, having a hinge or spring at one end, and a catch or loop at the other.

Brooches of the safety-pin type (fibulae) were extensively used in antiquity, but only within definite limits of time and place. They seem to have been unknown to the Egyptians, and to the oriental nations untouched by Greek influence. In lands adjacent to Greece, they do not occur in Crete or at Hissarlik. The place of origin cannot as yet be exactly determined, but it would seem to have been in central Europe, towards the close of the Bronze Age, somewhat before 1000 B.C. The earliest form is little more than a pin, bent round for security, with the point caught against the head. One such actual pin has been found. In its next simplest form, very similar to that of the modern safety-pin (in which the coiled spring forces the point against the catch), it occurs in the lower city of Mycenae, and in late deposits of the Mycenaean Age, such as at Enkomi in Cyprus. It occurs also (though rarely) in the "terramare" deposits of the Po valley, in the Swiss lake-dwellings of the later Bronze Age, in central Italy, in Hungary and in Bosnia. (fig. 1).[1]



From the comparatively simple initial form, the fibula developed in different lines of descent, into different shapes, varying according to the structural feature which was emphasized. On account of the number of local variations, the subject is extremely complex, but the main lines of development were approximately as follows.

Towards the end of the Bronze Age the safety-pin was arched into a bow, so as to include a greater amount of stuff in its compass.

In the older Iron Age or "Hallstatt period" the bow and its accessories are thickened and modified in various directions, so as to give greater rigidity, and prominences or surfaces for decoration. The chief types have been conveniently classed by [v.04 p.0642] Montelius in four main groups, according to the characteristic forms:—

I. The wire of the catch-plate is hammered into a flat disk, on which the pin rests (fig. 2)



II. The bow is thickened towards the middle, so as to assume the "leech" shape, or it is hollowed out underneath, into the "boat" form. The catch-plate is only slightly turned up, but it becomes elongated, in order to mask the end of a long pin (fig. 3).

III. The catch-plate is flattened out as in group I., but additional convolutions are added to the bow (fig. 4).

IV. The bow is convoluted (but the convolutions are sometimes represented by knobs); the catch-plate develops as in group II. (fig. 5). For further examples of the four types, see Antiquities of Early Iron Age in British Museum, p. 32.

Among the special variations of the early form, mention should be made of the fibulae of the geometric age of Greece, with an exaggerated development of the vertical portion of the catch-plate (fig. 6).



The example shown in fig. 7 is an ornate development of type II. above.

In the later Iron Age (or early La Tene period) the prolongation of the catch-plate described in the second and fourth groups above has a terminal knob ornament, which is reflexed upwards, at first slightly (fig. 8), and then to a marked extent, turning back towards the bow.

A far-reaching change in the design was at the same time brought about by a simple improvement in principle, apparently introduced within the area of the La Tene culture. Instead of a unilateral spring—that is, of one coiled on one side only of the bow as commonly in the modern safety-pin—the brooch became bilateral. The spring was coiled on one side of the axis of the bow, and thence the wire was taken to the other side of the axis, and again coiled in a corresponding manner before starting in a straight line to form the pin. Once invented, the bilateral spring became almost universal, and its introduction serves to divide the whole mass of ancient fibulae into an older and a younger group.



With the progress of the La Tene period (300-1 B.C.) the reflection of the catch-plate terminal became yet more marked, until it became practically merged in the bow (fig. 9). Meanwhile, the bilateral spring described above was developing into two marked projections on each side of the axis. In order to give the double spring strength and protection it was given a metal core, and a containing tube. When the core had been provided the pin was no longer necessarily a continuation of the bow, and it became in fact a separate member, as in a modern brooch of a non-safety-pin type, and was no longer actuated by its own spring.

The T-shaped or "cross-bow" fibula was thus developed. During the first centuries of the Empire it attained great size and importance (figs. 10-12). The form is conveniently dated at its highest development by its occurrence on the ivory diptych of Stilicho at Monza (c. A.D. 400).

In the tombs of the Frankish and kindred Teutonic tribes between the 5th and 9th centuries the crossbar of the T becomes a yet more elaborately decorated semicircle, often surrounded by radial knobs and a chased surface. The base of the shaft is flattened out, and is no less ornate (fig. 13). At the beginning of this period the fibula of King Childeric (A.D. 481) has a singularly complicated pin-fastening.



So far we have traced the history of the safety-pin form of brooch. Concurrently with it, other forms of brooch were developed in which the safety-pin principle is either absent or effectually disguised. One such form is that of the circular medallion brooch. It is found in Etruscan deposits of a fully developed style, and is commonly represented in Greek and Roman sculptures as a stud to fasten the cloak on the shoulder. In the Roman provinces the circular brooches are very numerous, and are frequently decorated with inlaid stone, paste or enamel. Another kind of brooch, also known from early times, is in the form of an animal. In the early types the animal is a decorative appendage, but in later examples it forms the body of the brooch, to which a pin like the modern brooch-pin is attached underneath. Both of these shapes, namely the medallion and the animal form, are found in Frankish cemeteries, together with the later variations of the T-shaped brooch described above. Such brooches were made in gold, silver or bronze, adorned with precious stones, filigree work, or enamel; but whatever the richness of the material, the pin was nearly always of iron. The Scandinavian or northern group of T-shaped brooches are in their early forms indistinguishable from those of the Frankish tombs, but as time went on they became more massive, and richly decorated with intricate devices (perhaps brought in by Irish missionary influence), into which animal forms were introduced. The period covered is from the 5th to the 8th centuries.



The T-form, the medallion-form, and (occasionally) the animal forms occur in Anglo-Saxon graves in England. In Kent the medallion-form predominates. The Anglo-Saxon brooches [v.04 p.0643] were exquisite works of art, ingeniously and tastefully constructed. They are often of gold, with a central boss, exquisitely decorated, the flat part of the brooch being a mosaic of turquoises, garnets on gold foil, mother of pearl, &c. arranged in geometric patterns, and the gold work enriched with filigree or decorated with dragonesque engravings.



The Scandinavian brooches of the Viking period (A.D. 800-1050) were oval and convex, somewhat in the form of a tortoise. In their earliest form they occur in the form of a frog-like animal, itself developed from the previous Teutonic T-shaped type. With the introduction of the intricate system of ornament described above, the frog-like animal is gradually superseded by purely decorative lines. The convex bowls are then worked a jour with a perforated upper shell of chased work over an under shell of impure bronze, gilt on the convex side. These outer cases are at last decorated with open crown-like ornament and massive projecting bosses. The geographical distribution of these peculiar brooches indicates the extent of the conquests of the Northmen. They occur in northern Scotland, England, Ireland, Iceland, Normandy and Livonia.



The Celtic group is characterized by the penannular form of the ring of the brooch and the greater length of the pin. The penannular ring, inserted through a hole at the head of the long pin, could be partially turned when the pin had been thrust through the material in such a way that the brooch became in effect a buckle. These brooches are usually of bronze or silver, chased or engraved with intricate designs of interlaced or dragonesque work in the style of the illuminated Celtic manuscripts of the 7th, 8th and 9th centuries. The Hunterston brooch, which was found at Hawking Craig in Ayrshire, is a well-known example of this style. Silver brooches of immense size, some having pins 15 in. in length, and the penannular ring of the brooch terminating in large knobs resembling thistle heads, are occasionally found in Viking hoards of this period, consisting of bullion, brooches and Cufic and Anglo-Saxon coins buried on Scottish soil. In medieval times the form of the brooch was usually a simple, flat circular disk, with open centre, the pin being equal in length to the diameter of the brooch. They were often inscribed with religious and talismanic formulae. The Highland brooches were commonly of this form, but the disk was broader, and the central opening smaller in proportion to the size of the brooch. They were ornamented in the style so common on Highland powder-horns, with engraved patterns of interlacing work and foliage, arranged in geometrical spaces, and sometimes mingled with figures of animals.

(A. H. SM.)

[1] The illustrations of this article are from Dr Robert Forrer's Reallexikon, by permission of W. Spemann, Berlin and Stuttgart.

BROOKE, FRANCES (1724-1789), English novelist and dramatist, whose maiden name was Moore, was born in 1724. Of her novels, some of which enjoyed considerable popularity in their day, the most important were The History of Lady Julia Mandeville (1763), Emily Montague (1769) and The Excursion (1777). Her dramatic pieces and translations from the French are now forgotten. She died in January 1789.

BROOKE, FULKE GREVILLE, 1ST BARON (1554-1628), English poet, only son of Sir Fulke Greville, was born at Beauchamp Court, Warwickshire. He was sent in 1564, on the same day as his life-long friend, Philip Sidney, to Shrewsbury school. He matriculated at Jesus College, Cambridge, in 1568. Sir Henry Sidney, president of Wales, gave him in 1576 a post connected with the court of the Marches, but he resigned it in 1577 to go to court with Philip Sidney. Young Greville became a great favourite with Queen Elizabeth, who treated him with less than her usual caprice, but he was more than once disgraced for leaving the country against her wishes. Philip Sidney, Sir Edward Dyer and Greville were members of the "Areopagus," the literary clique which, under the leadership of Gabriel Harvey, supported the introduction of classical metres into English verse. Sidney and Greville arranged to sail with Sir Francis Drake in 1585 in his expedition against the Spanish West Indies, but Elizabeth peremptorily forbade Drake to take them with him, and also refused Greville's request to be allowed to join Leicester's army in the Netherlands. Philip Sidney, who took part in the campaign, was killed on the 17th of October 1586, and Greville shared with Dyer the legacy of his books, while in his Life of the Renowned Sir Philip Sidney he raised an enduring monument to his friend's memory. About 1591 Greville served for a short time in Normandy under Henry of Navarre. This was his last experience of war. In 1583 he became secretary to the principality of Wales, and he represented Warwickshire in parliament in 1592-1593, 1597, 1601 and 1620. In 1598 he was made treasurer of the navy, and he retained the office through the early years of the reign of James I. In 1614 he became chancellor and under-treasurer of the exchequer, and throughout the reign he was a valued supporter of the king's party, although in 1615 he advocated the summoning of a parliament. In 1618 he became commissioner of the treasury, and in 1621 he was raised to the peerage with the title of Baron Brooke, a title which had belonged to the family of his paternal grandmother, Elizabeth Willoughby. He received from James I. the grant of Warwick Castle, in the restoration of which he is said to have spent L20,000. He died on the 30th of September 1628 in consequence of a wound inflicted by a servant who was disappointed at not being named in his master's will. Brooke was buried in St Mary's church, Warwick, and on his tomb was inscribed the epitaph he had composed for himself: "Folk Grevill Servant to Queene Elizabeth Conceller to King James Frend to Sir Philip Sidney. Trophaeum Peccati."

A rhyming elegy on Brooke, published in Huth's Inedited Poetical Miscellanies, brings charges of extreme penuriousness against him, but of his generous treatment of contemporary writers there is abundant testimony. His only works published during his lifetime were four poems, one of which is the elegy on Sidney which appeared in The Phoenix Nest (1593), and the Tragedy of Mustapha. A volume of his works appeared in 1633, another of Remains in 1670, and his biography of Sidney in 1652. He wrote two tragedies on the Senecan model, Alaham and Mustapha. The scene of Alaham is laid in Ormuz. The development of the piece fully bears out the gloom of the prologue, in which the ghost of a former king of Ormuz reveals the magnitude of the curse about to descend on the doomed family. The theme of Mustapha is borrowed from Madeleine de Scudery's Ibrahim ou l'illustre Bassa, and turns on the ambition of the sultana Rossa. The choruses of these plays are really philosophical dissertations, and the connexion with the rest of the drama is often very slight. In Mustapha, for instance, the third chorus is a dialogue between Time and Eternity, while the fifth consists of an invective against the evils of superstition, followed by a chorus of priests that does nothing to dispel [v.04 p.0644] the impression of scepticism contained in the first part. He tells us himself that the tragedies were not intended for the stage. Charles Lamb says they should rather be called political treatises. Of Brooke Lamb says, "He is nine parts Machiavel and Tacitus, for one of Sophocles and Seneca.... Whether we look into his plays or his most passionate love-poems, we shall find all frozen and made rigid with intellect." He goes on to speak of the obscurity of expression that runs through all Brooke's poetry, an obscurity which is, however, due more to the intensity and subtlety of the thought than to any lack of mere verbal lucidity.

It is by his biography of Sidney that Fulke Greville is best known. The full title expresses the scope of the work. It runs: The Life of the Renowned Sr. Philip Sidney. With the true Interest of England as it then stood in relation to all Forrain Princes: And particularly for suppressing the power of Spain Stated by Him: His principall Actions, Counsels, Designes, and Death. Together with a short account of the Maximes and Policies used by Queen Elizabeth in her Government. He includes some autobiographical matter in what amounts to a treatise on government. He had intended to write a history of England under the Tudors, but Robert Cecil refused him access to the necessary state papers.

Brooke left no sons, and his barony passed to his cousin, Robert Greville (c. 1608-1643), who thus became 2nd Lord Brooke. This nobleman was imprisoned by Charles I. at York in 1639 for refusing to take the oath to fight for the king, and soon became an active member of the parliamentary party; taking part in the Civil War he defeated the Royalists in a skirmish at Kineton in August 1642. He was soon given a command in the midland counties, and having seized Lichfield he was killed there on the 2nd of March 1643. Brooke, who is eulogized as a friend of toleration by Milton, wrote on philosophical, theological and current political topics. In 1746 his descendant, Francis Greville, the 8th baron (1710-1773), was created earl of Warwick, a title still in his family.

Dr A.B. Grosart edited the complete works of Fulke Greville for the Fuller Worthies Library in 1870, and made a small selection, published in the Elizabethan Library (1894). Besides the works above mentioned, the volumes include Poems of Monarchy, A Treatise of Religion, A Treatie of Humane Learning, An Inquisition upon Fame and Honour, A Treatie of Warres, Caelica in CX Sonnets, a collection of lyrics in various forms, a letter to an "Honourable Lady," a letter to Grevill Varney in France, and a short speech delivered on behalf of Francis Bacon, some minor poems, and an introduction including some of the author's letters. The life of Sidney was reprinted by Sir S. Egerton Brydges in 1816; and with an introduction by N. Smith in the "Tudor and Stuart Library" in 1907; Caelica was reprinted in M.F. Crow's "Elizabethan Sonnet Cycles" in 1898. See also an essay in Mrs. C.C. Stopes's Shakespeare's Warwickshire Contemporaries (1907).

BROOKE, HENRY (c. 1703-1783), Irish author, son of William Brooke, rector of Killinkere, Co. Cavan, was born at Rantavan in the same county, about 1703. His mother was a daughter of Simon Digby, bishop of Elphin. Dr Thomas Sheridan was one of his schoolmasters, and he was entered at Trinity College, Dublin, in 1720; in 1724 he was sent to London to study law. He married his cousin and ward, Catherine Meares, before she was fourteen. Returning to London he published a philosophical poem in six books entitled Universal Beauty (1735). He attached himself to the party of the prince of Wales, and took a small house at Twickenham near to Alexander Pope. In 1738 he translated the first and second books of Tasso's Gerusalemme liberata, and in the next year he produced a tragedy, Gustavas Vasa, the Deliverer of his Country. This play had been rehearsed for five weeks at Drury Lane, but at the last moment the performance was forbidden. The reason of this prohibition was a supposed portrait of Sir Robert Walpole in the part of Trollio. In any case the spirit of fervent patriotism which pervaded the play was probably disliked by the government. The piece was printed and sold largely, being afterwards put on the Irish stage under the title of The Patriot. This affair provoked a satirical pamphlet from Samuel Johnson, entitled "A Complete Vindication of the Licensers of the Stage from the malicious and scandalous Aspersions of Mr Brooke" (1739). His wife feared that his connexion with the opposition was imprudent, and induced him to return to Ireland. He interested himself in Irish history and literature, but a projected collection of Irish stories and a history of Ireland from the earliest times were abandoned in consequence of disputes about the ownership of the materials. During the Jacobite rebellion of 1745 Brooke issued his Farmer's Six Letters to the Protestants of Ireland (collected 1746) the form of which was suggested by Swift's Drapier's Letters. For this service he received from the government the post of barrack-master at Mullingar, which he held till his death. He wrote other pamphlets on the Protestant side, and was secretary to an association for promoting projects of national utility. About 1760 he entered into negotiations with leading Roman Catholics, and in 1761 he wrote a pamphlet advocating alleviation of the penal laws against them. He is said to have been the first editor of the Freeman's Journal, established at Dublin in 1763. Meanwhile he had been obliged to mortgage his property in Cavan, and had removed to Co. Kildare. Subsequently a bequest from Colonel Robert Brooke enabled him to purchase an estate near his old home, and he spent large sums in attempting to reclaim the waste-land. His best-known work is the novel entitled The Fool of Quality; or the History of Henry Earl of Moreland, the first part of which was published in 1765; and the fifth and last in 1770. The characters of this book, which relates the education of an ideal nobleman by an ideal merchant-prince, are gifted with a "passionate and tearful sensibility," and reflect the real humour and tenderness of the writer. Brooke's religious and philanthropic temper recommended the book to John Wesley, who edited (1780) an abridged edition, and to Charles Kingsley, who published it with a eulogistic notice in 1859. Brooke had a large family, but only two children survived him. His wife's death seriously affected him, and he died at Dublin in a state of mental infirmity on the 10th of October 1783.

His daughter, Charlotte Brooke, published The Poetical Works of Henry Brooke in 1792, but was able to supply very little biographical material. Other sources for Brooke's biography are C. H. Wilson, Brookiana (2 vols., 1804), and a biographical preface by E. A. Baker prefixed to a new edition (1906) of The Fool of Quality. Brooke's other works include several tragedies, only some of which were actually staged. He also wrote: Jack the Giant Queller (1748), an operatic satire, the repetition of which was forbidden on account of its political allusions; "Constantia, or the Man of Lawe's Tale" (1741), contributed to George Ogle's Canterbury Tales modernized; Juliet Grenville; or the History of the Human Heart (1773), a novel; and some fables contributed to Edward Moore's Fables for the Female Sex (1744).

BROOKE, SIR JAMES (1803-1868), English soldier, traveller and raja of Sarawak, was born at Coombe Grove near Bath, on the 29th of April 1803. His father, a member of the civil service of the East India Company, had long lived in Bengal. His mother was a woman of superior mind, and to her care he owed his careful early training. He received the ordinary school education, entered the service of the East India Company, and was sent out to India about 1825. On the outbreak of the Burmese War he was despatched with his regiment to the valley of the Brahmaputra; and, being dangerously wounded in an engagement near Rungpore, was compelled to return home (1826). After his recovery he travelled on the continent before going to India, and circumstances led him soon after to leave the service of the company. In 1830 he made a voyage to China, and during his passage among the islands of the Indian Archipelago, so rich in natural beauty, magnificence and fertility, but occupied by a population of savage tribes, continually at war with each other, and carrying on a system of piracy on a vast scale and with relentless ferocity, he conceived the great design of rescuing them from barbarism and bringing them within the pale of civilization. His purpose was confirmed by observations made during a second visit to China, and on his return to England he applied himself in earnest to making the necessary preparations. Having succeeded on the death of his father to a large property, he bought and equipped a yacht, the "Royalist," of 140 tons burden, and for three years tested its capacities and trained his crew of [v.04 p.0645] twenty men, chiefly in the Mediterranean. At length, on the 27th of October 1838, he sailed from the Thames on his great adventure. On reaching Borneo, after various delays, he found the raja Muda Hassim, uncle of the reigning sultan, engaged in war in the province of Sarawak with several of the Dyak tribes, who had revolted against the sultan. He offered his aid to the raja; and with his crew, and some Javanese who had joined them, he took part in a battle with the insurgents, and they were defeated. For his services the title of raja of Sarawak was conferred on him by Muda Hassim, the former raja being deprived in his favour. It was, however, some time before the sultan could be induced to confirm his title (September 1841). During the next five years Raja Brooke was engaged in establishing his power, in making just reforms in administration, preparing a code of laws and introducing just and humane modes of dealing with the degraded subjects of his rule. But this was not all. He looked forward to the development of commerce as the most effective means of putting an end to the worst evils that afflicted the archipelago; and in order to make this possible, the way must first be cleared by the suppression, or a considerable diminution, of the prevailing piracy, which was not only a curse to the savage tribes engaged in it, but a standing danger to European and American traders in those seas. Various expeditions were therefore organized and sent out against the marauders, Dyaks and Malays, and sometimes even Arabs. Captain (afterwards Admiral Sir Harry) Keppel, and other commanders of British ships of war, received permission to co-operate with Raja Brooke in these expeditions. The pirates were attacked in their strongholds, they fought desperately, and the slaughter was immense. Negotiations with the chiefs had been tried, and tried in vain. The capital of the sultan of Borneo was bombarded and stormed, and the sultan with his army routed. He was, however, soon after restored to his dominion. So large was the number of natives, pirates and others, slain in these expeditions, that the "head-money" awarded by the British government to those who had taken part in them amounted to no less than L20,000. In October 1847 Raja Brooke returned to England, where he was well received by the government; and the corporation of London conferred on him the freedom of the city. The island of Labuan, with its dependencies, having been acquired by purchase from the sultan of Borneo, was erected into a British colony, and Raja Brooke was appointed governor and commander-in-chief. He was also named consul-general in Borneo. These appointments had been made before his arrival in England. The university of Oxford conferred on him the honorary degree of D.C.L., and in 1848 he was created K.C.B. He soon after returned to Sarawak, and was carried thither by a British man-of-war. In the summer of 1849 he led an expedition against the Seribas and Sakuran Dyaks, who still persisted in their piratical practices and refused to submit to British authority. Their defeat and wholesale slaughter was a matter of course. At the time of this engagement Sir James Brooke was lying ill with dysentery. He visited twice the capital of the sultan of Sala, and concluded a treaty with him, which had for one of its objects the expulsion of the sea-gypsies and other tribes from his dominions. In 1851 grave charges with respect to the operations in Borneo were brought against Sir James Brooke in the House of Commons by Joseph Hume and other members, especially as to the "head-money" received. To meet these accusations, and to vindicate his proceedings, he came to England. The evidence adduced was so conflicting that the matter was at length referred to a royal commission, to sit at Singapore. As the result of its investigation the charges were declared to be "not proven." Sir James, however, was soon after deprived of the governorship of Labuan, and the head-money was abolished. In 1867 his house in Sarawak was attacked and burnt by Chinese pirates, and he had to fly from the capital, Kuching. With a small force he attacked the Chinese, recovered the town, made a great slaughter of them, and drove away the rest. In the following year he came to England, and remained there for three years. During this time he was attacked by paralysis, a public subscription was raised, and an estate in Devonshire was bought and presented to him. He made two more visits to Sarawak, and on each occasion had a rebellion to suppress. He spent his last days on his estate at Burrator in Devonshire, and died there, on the 11th of June 1868, being succeeded as raja of Sarawak by his nephew. Sir James Brooke was a man of the highest personal character, and he displayed rare courage both in his conflicts in the East and under the charges advanced against him in England.

His Private Letters (1838 to 1853) were published in 1853. Portions of his Journal were edited by Captains Munday and Keppel. (See also SARAWAK.)

BROOKE, STOPFORD AUGUSTUS (1832- ), English divine and man of letters, born at Letterkenny, Donegal, Ireland, in 1832, was educated at Trinity College, Dublin. He was ordained in the Church of England in 1857, and held various charges in London. From 1863 to 1865 he was chaplain to the empress Frederick in Berlin, and in 1872 he became chaplain in ordinary to Queen Victoria. But in 1880 he seceded from the Church, being no longer able to accept its leading dogmas, and officiated as a Unitarian minister for some years at Bedford chapel, Bloomsbury. Bedford chapel was pulled down about 1894, and from that time he had no church of his own, but his eloquence and powerful religious personality continued to make themselves felt among a wide circle. A man of independent means, he was always keenly interested in literature and art, and a fine critic of both. He published in 1865 his Life and Letters of F. W. Robertson (of Brighton), and in 1876 wrote an admirable primer of English Literature (new and revised ed., 1900), followed in 1892 by The History of Early English Literature (2 vols., 1892) down to the accession of Alfred, and English Literature from the Beginnings to the Norman Conquest (1898). His other works include various volumes of sermons; Poems (1888); Dove Cottage (1890); Theology in the English Poets—Cowper, Coleridge, Wordsworth, Burns (1874); Tennyson, his Art and Relation to Modern Life (1894); The Poetry of Robert Browning (1902); On Ten Plays of Shakespeare (1905); and The Life Superlative (1906).

BROOK FARM, the name applied to a tract of land in West Roxbury, Massachusetts, on which in 1841-1847 a communistic experiment was unsuccessfully tried. The experiment was one of the practical manifestations of the spirit of "Transcendentalism," in New England, though many of the more prominent transcendentalists took no direct part in it. The project was originated by George Ripley, who also virtually directed it throughout. In his words it was intended "to insure a more natural union between intellectual and manual labour than now exists; to combine the thinker and the worker, as far as possible, in the same individual; to guarantee the highest mental freedom by providing all with labour adapted to their tastes and talents, and securing to them the fruits of their industry; to do away with the necessity of menial services by opening the benefits of education and the profits of labour to all; and thus to prepare a society of liberal, intelligent and cultivated persons whose relations with each other would permit a more simple and wholesome life than can be led amidst the pressure of our competitive institutions." In short, its aim was to bring about the best conditions for an ideal civilization, reducing to a minimum the labour necessary for mere existence, and by this and by the simplicity of its social machinery saving the maximum of time for mental and spiritual education and development. At a time when Ralph Waldo Emerson could write to Thomas Carlyle, "We are all a little wild here with numberless projects of social reform; not a reading man but has a draft of a new community in his waistcoat pocket,"—the Brook Farm project certainly did not appear as impossible a scheme as many others that were in the air. At all events it enlisted the co-operation of men whose subsequent careers show them to have been something more than visionaries. The association bought a tract of land about 10 m. from Boston, and in the summer of 1841 began its enterprise with about twenty members. In September the "Brook Farm Institute of Agriculture and Education" was formally organized, the members [v.04 p.0646] signing the Articles of Association and forming an unincorporated joint-stock company. The farm was assiduously, if not very skilfully, cultivated, and other industries were established—most of the members paying by labour for their board—but nearly all of the income, and sometimes all of it, was derived from the school, which deservedly took high rank and attracted many pupils. Among these were included George William Curtis and his brother James Burrill Curtis, Father Isaac Thomas Hecker (1819-1888), General Francis C. Barlow (1834-1896), who as attorney-general of New York in 1871-1873 took a leading part in the prosecution of the "Tweed Ring." For three years the undertaking went on quietly and simply, subject to few outward troubles other than financial, the number of associates increasing to seventy or eighty. It was during this period that Nathaniel Hawthorne had his short experience of Brook Farm, of which so many suggestions appear in the Blithedale Romance, though his preface to later editions effectually disposed of the idea—which gave him great pain—that he had either drawn his characters from persons there, or had meant to give any actual description of the colony. Emerson refused, in a kind and characteristic letter, to join the undertaking, and though he afterwards wrote of Brook Farm with not uncharitable humour as "a perpetual picnic, a French Revolution in small, an age of reason in a patty-pan," among its founders were many of his near friends. In 1844 the growing need of a more scientific organization, and the influence which F.M.C. Fourier's doctrines, as modified by Albert Brisbane (1809-1890), had gained in the minds of Ripley and many of his associates, combined to change the whole plan of the community. It was transformed, with the strong approval of all its chief members and the consent of the rest, into a Fourierist "phalanx" in 1845. There was an accession of new members, a momentary increase of prosperity, a brilliant new undertaking in the publication of a weekly journal, the Harbinger, in which Ripley, Charles A. Dana, Francis G. Shaw and John S. Dwight were the chief writers, and to which James Russell Lowell, J.G. Whittier, George William Curtis, Parke Godwin, T.W. Higginson, Horace Greeley and many more now and then contributed. But the individuality of the old Brook Farm was gone. The association was not rescued even from financial troubles by the change. With increasing difficulty it kept on till the spring of 1846, when a fire which destroyed its nearly completed "phalanstery" brought losses which caused, or certainly gave the final ostensible reason for, its dissolution. The experiment was abandoned in the autumn of 1847. Besides Ripley and Hawthorne, the principal members of the community were Charles A. Dana, John S. Dwight, Minot Pratt (c. 1805-1878), the head farmer, who, like George Partridge Bradford (1808-1890), left in 1845, and Warren Burton (1810-1866) a preacher and, later, a writer on educational subjects. Indirectly connected with the experiment, also, as visitors for longer or shorter periods but never as regular members, were Emerson, Amos Bronson Alcott, Orestes A. Brownson, Theodore Parker and William Henry Channing, Margaret Fuller and Elizabeth Palmer Peabody. The estate itself, after passing through various hands, came in 1870 into the possession of the "Association of the Evangelical Lutheran Church for Works of Mercy," which established here an orphanage, known as the "Martin Luther Orphan Home."

The best account of Brook Farm is Lindsay Swift's Brook Farm, Its Members, Scholars and Visitors (New York, 1900). Brook Farm: Historic and Personal Memoirs (Boston, 1894), is by Dr J.T. Codman, one of the pupils in the school. See also Morris Hillquit's History of Socialism in the United States (New York, 1903).

(E. L. B.)



Pellia epiphylla (fig. 2) can be found at any season growing in large patches on the damp soil of woods, banks, &c. The broad flat thallus is green and may be a couple of inches long. It is sparingly branched, the branching being apparently dichotomous; the growing point is situated in a depression at the anterior end of each branch. The wing-like lateral portions of the thallus gradually thin out from the midrib; from the projecting lower surface of this numerous rhizoids spring. These are elongated superficial cells, and serve to fix the thallus to the soil and obtain water and salts from it. No leaf-like appendages are borne on the thallus, but short glandular hairs occur behind the apex. The plant is composed throughout of very similar living cells, the more superficial ones containing numerous chlorophyll grains, while starch is stored in the internal cells of the midrib. The cells contain a number of oil-bodies the function of which is imperfectly understood. The growth of the thallus proceeds by the regular segmentation of a single apical cell. The sexual organs are borne on the upper surface, and both antheridia and archegonia occur on the same branch (fig. 3, A). The antheridia (an) are scattered over the middle region of the thallus, and each is surrounded by a tubular upgrowth from the surface. The archegonia (ar) are developed in a group behind the apex, and the latter continues to grow for a time after their formation, so that they come to be seated in a depression of the upper surface. They are further protected by the growth of the hinder margin of the depression to form a scale-like involucre (in). Fertilization takes place about June, and the sporogonium is fully developed by the winter. The embryo developed from the fertilized ovum consists at first of a number of tiers of cells. Its terminal tier gives rise to the capsule, the first divisions in the four cells of the tier marking off the wall of the capsule from the cells destined to produce the spores. In fig. 4, C, which represents a longitudinal section of a young embryo of Pellia, these archesporial cells are shaded. The tiers below give rise to the seta and foot. The mature sporogonium (fig. 3, B) consists of the foot embedded in the tissue of the thallus, the seta, which remains short until just before the shedding of the spores, and the spherical capsule. It remains for long enclosed within the calyptra formed by the further development of the archegonial wall and surmounted by the neck of the archegonium. The calyptra is ultimately burst through, and in early spring the seta elongates rapidly, raising the dark-coloured capsule (fig. 2). In the young condition the wall of the capsule, which consists of two layers of cells, encloses a mass of similar cells developed from the archesporium. Some of these become spore-mother-cells and give rise by cell division to four spores, while others remain undivided and become the elaters. The latter are elongated spindle-shaped cells with thick brown spiral bands on the inside of their thin walls. They radiate out from a small plug of sterile cells projecting into the base of the capsule, and some are attached to this, while others lie free among the spores. The latter are large, and at first are unicellular; but in Pellia, which in this respect is exceptional, they commence their further development within the capsule, and thus consist of several cells when shed. [v.04 p.0647] The cells of the capsule wall have incomplete, brown, thickened rings on their walls, and the capsule opens by splitting into four valves, which bend away from one another, allowing the loose spores to be readily dispersed by the wind, assisted by the hygroscopic movements of the elaters. On falling upon damp soil the spores germinate, growing into a thallus, which gradually attains its full size and bears sexual organs.



While the general course of the life-history of all liverworts resembles that of Pellia, the three great groups into which they are divided differ from one another in the characters of both generations. Each group exhibits a series leading from more simple to more highly organized forms, and the differentiation has proceeded on distinct and to some extent divergent lines in the three groups. The Marchantiales are a series of thalloid forms, in which the structure of the thallus is specialized to enable them to live in more exposed situations. The lowest members of the series (Riccia) possess the simplest sporogonia known, consisting of a wall of one layer of cells enclosing the spores. In the higher forms a sterile foot and seta is present, and sterile cells or elaters occur with the spores. The lower members of the Jungermanniales are also thalloid, but the thallus never has the complicated structure characteristic of the Marchantiales, and progress is in the direction of the differentiation of the plant into stem and leaf. Indications of how this may have come about are afforded by the lower group of the Anacrogynous Jungermanniaceae, and throughout the Acrogynous Jungermanniacae the plant has well-marked stem and leaves. The sporogonium even in the simplest forms has a sterile foot, but in this series also the origin of elaters from sterile cells can be traced. The Anthocerotales are a small and very distinct group, in which the gametophyte is a thallus, while the sporogonium possesses a sterile columella and is capable of long-continued growth and spore production. The mode of development of the sporogonium presents important differences in the three series that may be briefly referred to here. In fig. 4 young sporogonia of a number of liverworts are shown in longitudinal section, and the archesporial cells from which the spores and elaters will arise are shaded. In Riccia (fig. 4, A) the whole mass of cells derived from the ovum forms a spherical capsule, the only sterile tissue being the single layer of peripheral cells forming the wall. In other Marchantiales (fig. 4, B) the lower half of the embryo separated by the first transverse wall (1, I) forms the sterile foot and seta, while in the upper half (ka) the peripheral layer forms the wall of the capsule, enclosing the archesporial cells from which spores and elaters arise. In the Jungermanniales (fig. 4, C, E, F) the embryo is formed of a number of tiers of cells, and the archesporium is defined by the first divisions parallel to the surface in the cells of one or more of the upper tiers; a number of tiers go to form the seta and foot, while the lowest segment (a) usually forms a small appendage of the latter. In the Anthocerotales (fig. 4, D) the lowest tiers form the foot, and the terminal tier the capsule. The first periclinal divisions in the cells of the terminal tier separate a central group of cells which form the sterile columella (col). The archesporium arises by the next divisions in the outer layer of cells, and thus extends over the summit of the columella. In none of the liverworts does the sporogonium develop by means of an apical cell, as is the rule in mosses.

Leaving details of form and structure to be considered under the several groups, some general features of the Hepaticae may be looked at here in relation to the conditions under which the plants live. The organization of the gametophyte stands in the closest relation to the factors of light and moisture in the environment. With hardly an exception the liverworts are dorsiventral, and usually one side is turned to the substratum and the other exposed to the light. In thalloid forms a thinner marginal expansion or a definite wing increasing the surface exposed to the light can be distinguished from a thicker midrib serving for storage and conduction. The leaves and stem of the foliose forms effect the same division of labour in another way. The relation of the plant to its water supply varies within the group. In the Marchantiales the chief supply is obtained from the soil by the rhizoids, and its loss in transpiration is regulated and controlled. In most liverworts, on the other hand, water is absorbed directly by the whole general surface, and the rhizoids are of subordinate importance. Many forms only succeed in a constantly humid atmosphere, while others sustain drying for a period, though their powers of assimilation and growth are suspended in the dry state. The cell-walls are capable of imbibing water rapidly, and their thickness stands in relation to this rather than to the prevention of loss of water from the plant. The large surface presented by the leafy forms facilitates the retention and absorption of water. The importance of prolonging the moistened condition as long as possible is further shown by special adaptations to retain water either between the appressed lobes of the leaves or in special pitcher-like sacs. In thalloid forms fimbriate or lobed margins or outgrowths from the surface lead to the same result. Sometimes adaptations to protect the plant during seasons of drought, such as the rolling up of the thallus in many xerophytic Marchantiales, can be recognized, but more often a prolonged dry season is survived in some resting state. The formation of subterranean tubers, which persist when the rest of the plant is killed by drought, is an interesting adaptation to this end, and is found in all three groups (e.g. in species of Riccia, Fossombronia and Anthoceros). No examples of total saprophytism or of parasitism are known, but two interesting cases of a symbiosis with other organisms which is probably a mutually beneficial one, though the nature of the physiological relation between the organisms is not clearly established, may be mentioned. Fungal hyphae occur in the rhizoids and in the cells of the lower region of the thallus of many liverworts, as in the endotrophic mycorhiza of higher plants. Colonies of Nostoc are constantly found in the Anthocerotaceae and in Blasia. In the latter they are protected by special concave scales, while in the Anthocerotaceae they occupy some of the mucilage slits between the cells of the lower surface of the thallus.

Other adaptations concern the protection of the sexual organs and sporogonia, and the retention of water in the neighbourhood of the archegonia to enable the spermatozoid to reach the ovum. In thalloid forms the sexual organs are often sunk in depressions, while in the foliose forms protection is afforded by the surrounding leaves. In addition special involucres around the archegonia have arisen independently in several series. The characters of the sporogonium have as their object the nutrition and effective distribution of the spores, and only exceptionally, as in the Anthocerotaceae, are concerned with independent assimilation. In most forms the capsule is raised above the general surface at the time of opening, usually by the rapid growth of the seta, but in the Marchantiaceae by the sporogonia being raised on a special archegoniophore. The elaters serve as lines of conduction of plastic material to the developing spores, and later usually assist in their dispersal. The spores, with few exceptions, are unicellular when shed, and may develop at once or after a resting period. In their germination a short filament of a few cells is usually developed, and the apical cell of the plant is established in the terminal cell. In other cases a small plate or mass of cells is formed. With one or two exceptions, however, this preliminary [v.04 p.0648] phase, which may be compared with the protonema of mosses, is of short duration.

The power of vegetative propagation is widely spread. When artificially divided small fragments of the gametophyte are found to be capable of growing into new individuals. Apart from the separation of branches by the decay of older portions, special gemmae are found in many species. In Aneura the contents of superficial cells, after becoming surrounded by a new wall and dividing, escape as bi-cellular gemmae. Usually the gemmae arise by the outgrowth of superficial cells, and become free by breaking away from their stalk. When separated they may be single cells or consist of two or numerous cells. In Blasia and Marchantia the gemmae are formed within tubular or cup-shaped receptacles, out of which they are forced by the swelling of mucilage secreted by special hairs.



Marchantiales.—The plants of this group are most abundant in warm sunny localities, and grow for the most part on soil or rocks often in exposed situations. Nine genera are represented in Britain. Targionia is found on exposed rocks, but the other forms are less strikingly xerophytic; Marchantia polymorpha and Lunularia spread largely by the gemmae formed in the special gemma-cups on the thallus, and occur commonly in greenhouses. The large thallus of Conocephalus covers stones by the waterside, while Dumortiera is a hygrophyte confined to damp and shady situations. Among the Ricciaceae, most of which grow on soil, Ricciocarpus and Riccia natans occur floating on still water. The dorsiventral thallus is constructed on the same plan throughout the group, and shows a lower region composed of cells containing little chlorophyll and an upper stratum specialized for assimilation and transpiration. The lower region usually forms a more or less clearly marked midrib, and consists of parenchymatous cells, some of which may contain oil-bodies or be differentiated as mucilage cells or sclerenchyma fibres. Behind the apex, which has a number of initial cells, a series of amphigastria or ventral scales is formed. These consist of a single layer of cells, and their terminal appendages often fold over the apex and protect it. Usually they stand in two rows, but sometimes accessory rows occur, and in Riccia only a single median row is present. The thallus bears two sorts of rhizoids, wider ones with smooth walls which grow directly down into the soil, and longer, narrower ones, with peg-like thickenings of the wall projecting into the cell-cavity. The peg-rhizoids, which are peculiar to the group, converge under shelter of the amphigastria to the midrib, beneath which they form a wick-like strand. Through this water is conducted by capillarity as well as in the cell cavities. The upper stratum of the thallus is constructed to regulate the giving off of the water thus absorbed. It consists of a series of air-chambers (fig. 6, B) formed by certain lines of the superficial cells growing up from the surface, and as the thallus increases in area continuing to divide so as to roof in the chamber. The layer forming the roof is called the "epidermis," and the small opening left leading into the chamber is bounded by a special ring of cells and forms the "stoma" or air-pore. In most species of Riccia the air-chambers are only narrow passages, but in the other Marchantiales they are more extended. In the simplest cases the sides and base of the chambers perform the work of assimilation (e.g. Corsinia). Usually the surface is extended by the development of partitions in the chambers (Reboulia), or by the growth from the floor of the chamber of short filaments of chlorophyllous cells (Targionia. Marchantia, fig. 6). The stomata may be simply surrounded by one or more series of narrower cells, or, as in the thallus of Marchantia and on the archegoniophores of other forms, may become barrel-shaped structures by the division of the ring of cells bounding the pore. In some cases the lowermost circle of cells can be approximated so as to close the pore. In Dumortiera the air-chambers are absent, their formation being only indicated at the apex.



The sexual organs are always situated on the morphologically upper surface of the thallus. In Riccia they are scattered singly and protected by the air-chamber layer. The scattered position of the antheridia is also found in some of the higher forms, but usually they are grouped on special antheridiophores which in Marchantia are stalked, disk-shaped branch-systems (fig. 5). The individual antheridia are sunk in depressions from which the spermatozoids are in some cases forcibly ejected. The archegonial groups in Corsinia are sunk in a depression of the upper surface, while in Targionia they are displaced to the lower side of the anterior end of a branch. In all the other forms they are borne on special archegoniophores which have the form of a disk-shaped head borne on a stalk. The archegoniophore may be an upgrowth from the dorsal surface of the thallus (e.g. Plagiochasma), or the apex of the branch may take part in its formation. When the disk, around which archegonia are developed at intervals, is simply raised on a stalk-like continuation of the branch, a single groove protecting a strand of peg-rhizoids is found on the ventral face of the stalk (Reboulia). In the highest forms (e.g. Marchantia) the archegoniophore corresponds to the repeatedly branched continuation of the thallus, and the archegonia arise in relation to the growing points which are displaced to the lower surface of the disk. In this case two grooves are found in the stalk. The archegonia are protected by being sunk in depressions of the disk or by a special two-lipped involucre. In Marchantia and Fimbriaria an additional investment termed in descriptive works the perianth, grows up around each fertilized archegonium (fig. 1, 3, d). The simple sporogonium found in the Ricciaceae (fig. 4, A) has been described above; as the spores develop, the wall of the spherical capsule is absorbed and the spores lie free in the calyptra, by the decay of which they are set free. In Corsinia the capsule has a well-developed foot, but the sterile cells found among the spore-mother-cells do not become elaters, but remain thin-walled and simply contribute to the nutrition of the spores. In all other forms elaters with spirally thickened walls are found. The seta is short, the capsule being usually raised upon the archegoniophore. Dehiscence takes place either by the upper portion of the capsule splitting into short teeth or falling away as a whole or in fragments as a sort of operculum. The spores on germination form a short germ-tube, in the terminal cell of which the apical cell is established, but the direction of growth of the young thallus is usually not in the same straight line as the germ-tube. The Marchantiales are divided into a number of groups which represent distinct lines of advance from forms like the Ricciaceae, but the details of their classification cannot be entered upon here. The general nature of the progression exhibited by the group as a whole will, however, be evident from the above account.

Jungermanniales.—This large series of liverworts, which presents great variety in the organization of the sexual generation, is divided into two main groups according to whether the formation of archegonia terminates the growth of the branch or does not utilize the apex. The latter condition is characteristic of the more primitive group of the Anacrogynous Jungermanniaceae, in which the branch continues its growth after the formation of archegonia so that they (and later the sporogonia) stand on the dorsal surface of the thallus or leafy plant. In the Acrogynous Jungermanniaceae the plant is throughout foliose, and the archegonia occupy the ends of the main shoot or of its branches. The antheridia are usually globular and long-stalked. The capsule opens by splitting into four halves.



Jungermanniaceae Anacrogynae.—The great range of form in the sexual plant is well illustrated by the nine genera of this group [v.04 p.0649] which occur in Britain. One thalloid form has already been described in Pellia (fig. 2). Sphaerocarpus, which occurs rarely in stubble fields, is in many respects one of the simplest of the liverworts. The small thallus bears the antheridia and archegonia, each of which is surrounded by a tubular involucre, on the upper surface of distinct individuals. The sporogonium has a small foot, but the sterile cells among the spores do not develop into elaters. The same is true of the capsule of Riella. The plants of this genus, none of the species of which are British, grow in shallow water rooted in the mud, and are unlike all other liverworts in appearance. The usually erect thallus has a broad wing-like outgrowth from the dorsal surface and two rows of rather large scales below. No provision for the opening of the capsule exists in either of these genera. In Aneura the form of the plant may be complicated by a division of labour between root-like, stem-like and assimilating branches of the thallus. The sexual organs are borne on short lateral branches, while in the related genus Metzgeria, which occurs on rocks and tree trunks, the small sexual branches spring from the lower surface of the midrib of the narrow thallus. In these two genera the elaters are attached to a sterile group of cells projecting into the upper end of the capsule, and on dehiscence remain connected with the tips of the valves. Pallavicinia and some related genera have a definite midrib and broad wings formed of one layer of cells, and are of interest owing to the presence of a special water-conducting strand in the midrib. This consists of elongated lignified cells with pitted walls. Blasia pusilla, which occurs commonly by ditches and streams, affords a transition to the foliose types. Its thallus (fig. 7) has thin marginal lobes of limited growth, which are comparable to the more definite leaves of other anacrogynous forms. The ventral surface bears flat scales in addition to the concave scales which, as mentioned above, are inhabited by Nostoc. This interesting liverwort produces two kinds of gemmae, and in the localities in which it grows is largely reproduced by their means. In Fossombronia, of which there are a number of British species, the plant consists of a flattened stem creeping on muddy soil and bearing two rows of large obliquely-placed leaves. The sexual organs are borne on the upper surface of the midrib, and the sporogonium is surrounded by a bell-shaped involucre which grows up after fertilization. Treubia, which grows on rotting wood in the mountain forests of Java, is similarly differentiated into stem and leaf, and is the largest liverwort known, reaching a length of thirty centimetres. Lastly Haplomitrium, a rare British genus, forms with the exotic Calobryum, an isolated group which is most naturally placed among the anacrogynous forms although the archegonia are in terminal groups. The erect branches bear three rows of leaves, and spring from a creeping axis from which root-like branches destitute of rhizoids extend into the substratum.



Jungermanniaceae Acrogynae.—The plant consists of leafy shoots, the origin of which can be understood in the light of the foliose forms described above. The great majority of existing liverworts belong to this group, the general plan of construction of which is throughout very similar. In Britain thirty-nine genera with numerous species are found. With few exceptions the stem grows by means of a pyramidal apical cell cutting off three rows of segments. Each segment gives rise to a leaf, but usually the leaves of the ventral row (amphigastria) are smaller and differently shaped from those of the two lateral rows; in a number of genera they are wanting altogether. Sometimes the leaves retain their transverse insertion on the stem, and the two lobes of which they consist are developed equally. More often they come to be obliquely inserted, the anterior edge of each leaf lying under or over the edge of the leaf in front. The two lobes are often unequally developed. In Scapania the upper lobe is the smaller, while in Radula, Poretta and the Lejeuneae this is the case with the lower lobe. The folding of one lobe against another assists in the retention of water. Pitcher-like structures have arisen in different ways in a number of genera, and are especially common in epiphytic forms (Frullania, Lepidolaena, Pleurozia). In some forms the leaves are finely divided, and along with the hair-like paraphyllia form a loose weft around the stem (Trichocolea). The rhizoids spring from the lower surface of the stem, and sometimes from the bases of the leaves. The branches arise below and by the side of the leaves.



The sexual organs may occur on the same or on distinct individuals. The antheridia are protected by leaves which are often modified in shape. The archegonia are borne at the apex of the main stem or of a lateral branch. A single archegonium may arise from the apical cell (Lejeunea); more commonly a number of others are formed from the surrounding segments. The leaves below the archegonial group are frequently modified in size and shape, but the chief protection is afforded by a tubular perianth, which corresponds to a coherent whorl of leaves and grows up independently of fertilization. The perianth serves also to enclose and protect the sporogonium during its development. In a number of forms belonging to different groups the end of the stem on which the sporogonium is borne grows downwards so as to form a hollow tubular sac enclosing the sporogonium; in other cases this marsupial sac is formed by the base of the sporogonium boring into the thickened end of the stem. The sac usually penetrates into the soil and bears rhizoids on its outer surface. Kantia, Calypogeia and Saccogyna are British forms, which have their sporogonia protected in this way. The sporogonium is very similar throughout the group (figs. 8, 9). At maturity the seta elongates rapidly, and the wall of the capsule splits more or less completely into four valves, allowing the elaters and spores to escape. In the Jubuloideae, which in other respects form a well-marked group, the seta is short and the elaters extend from the upper part of the capsule to the base; at dehiscence they remain fixed to the valves into which the capsule splits. The germinating spore usually forms a short filament, but in other cases a flat plate of cells growing by a two-sided apical cell is first formed (Radula, Lejeunea). In one or two tropical forms the pro-embryonic stage is prolonged, and leafy shoots only arise in connexion with the sexual organs. In Protocephalozia, which grows on bare earth in South America, this pro-embryo is filamentous, while in Lejeunea Metzgeriopsis, which grows on the leaves of living plants, it is a flat branched thallus closely applied to the substratum. Other cases of the plant being, with the exception of the sexual branches, apparently thalloid, are on the other hand to be explained as due to the reduction of the leaves and flattening of the stem of a shoot (Pteropsiella, Zoopsis).

The Acrogynous Jungermanniaceae fall into a number of natural groups, which cannot, however, be followed out here. They occur in very various situations, on the ground, on rocks and stones, on tree trunks, and, in the damp tropics, on leaves. Usually they form larger or smaller tufts of a green colour, but some forms have a reddish tint.



Anthocerotales.—This small and very natural group includes the three genera Anthoceros, Dendroceros and Notothylas, and stands in [v.04 p.0650] many respects in an isolated position among the Bryophyta. Three species of Anthoceros occur in Britain, growing on the damp soil of fields, ditches, &c. The dark green thallus has an ill-defined midrib, and is composed of parenchymatous cells. In each assimilating cell there is usually a single large chloroplast. The apical region, which has a single initial cell, is protected by mucilage secreted by the mucilage slits, which are small pit-like depressions between superficial cells of the lower surface. Mucilage is also often formed in intercellular spaces within the thallus. Colonies of Nostoc are constantly found living in some of the mucilage slits which then become enlarged. The sexual organs are scattered over the upper surface. The stalked globular antheridia are exceptional in being formed endogenously, and are situated in groups in special intercellular spaces. The superficial layer of cells bounding the cavity does not break down until the antheridia are nearly mature. Occasionally antheridia develop on the surface of shaded portions of the thallus. The necks of the archegonia hardly project above the general surface of the thallus. In structure and development they agree with other Hepaticae, though differences of detail exist. The young sporogonium is protected by a thick calyptra derived from the tissue of the thallus around the archegonium. The sporogonium consists of a large bulbous foot, the superficial cells of which grow out into processes, and a long capsule, which continues to grow for months by the activity of a zone of cells between it and the foot, and may attain the length of an inch and a half. The wall of the capsule is several layers of cells thick, and since the epidermis contains functional stomata and the underlying cells possess chlorophyll it is capable of assimilation. In the centre of the capsule is a strand of narrow elongated cells forming the columella, and between this and the wall spores mixed with elaters are formed from the dome-shaped archesporium, the origin of which has already been described (fig. 4, D). The capsule opens by splitting into two valves from the apex downwards, and the mature spores escape while others are developing in succession below. In Dendroceros, which grows as an epiphyte in the tropics, the thallus has a well-defined midrib and broad wings composed of a single layer of cells. The capsule is similar to that of Anthoceros, but has no stomata, and the elaters have spirally thickened walls. Some species of Anthoceros agree with it in these respects. Notothylas resembles Anthoceros in its thallus, but the sporogonium is much smaller. In some species, although the columella and archesporium arise in the usual way, both give rise to mingled spores and elaters, and no sterile columella is developed.

Musci (Mosses).

Though the number of species of mosses is far greater than of liverworts, the group offers much less diversity of form. The sexual generation is always a leafy plant, which is not developed directly from the spore but is borne on a well-marked and usually filamentous protonema. The general course of the life-history and the main features of form and structure will be best understood by a brief account of a particular example.



Funaria hygrometrica is a moss of very common occurrence even in towns on the soil of paths, at the foot of walls and in similar places. The small plants grow closely crowded in tufts, and consist of short leafy shoots attached to the soil by numerous fine rhizoids. The latter, in contrast to the rhizoids of liverworts, are composed of rows of elongated cells and are branched. The leaves are simple, and except for the midrib are only one layer of cells thick. The structure of the stem though simple is more complicated than in any liverwort. The superficial cells are thick-walled, and there is a central strand of narrow cells forming a water-conducting tissue. The small strand of elongated cells in the midrib of the leaf runs down into the stem, but is not usually connected with the central strand. The sexual organs are developed in groups at the apices, the antheridial group usually terminating the main axis while the archegonia are borne on a lateral branch. The brown tint of the hair-like paraphyses mixed with antheridia (fig. 15) makes the male branch conspicuous, while the archegonia have to be carefully looked for enclosed by the surrounding leaves (fig. 16, B). The sporogonium developed from the fertilized ovum grows by means of a two-sided apical cell (fig. 16 A), and is at first of uniform thickness. After a time the upper region increases in diameter and forms the capsule, while the lower portion forms the long seta and the foot which is embedded in the end of the stem. With the growth of the sporogonium the archegonial wall, which for a time kept pace with it, is broken through, the larger upper part terminated by the neck being carried up on the capsule as the calyptra, while the basal portion remains as a tubular sheath round the lower end of the seta (cf. figs. 16, C, and fig. 11, A, B). The seta widens out at the base of the capsule into a region known as the apophysis. The peripheral cells of the seta are thick-walled, and it has a central strand of elongated conducting cells. In the epidermis of the apophysis functional stomata, similar to those of the higher plants, are present and, since cells containing chlorophyll are present below the superficial layers of the apophysis and capsule, the sporogonium is capable of independent assimilation. The construction of the capsule will be best understood from the median longitudinal section (fig. 11, C). The central region extending between the apophysis and the operculum is composed of sterile tissue and forms the columella (c). Immediately around this is the layer of cells from which the spores will be developed (s), and the layers of cells on either side of this form the walls of the spore-sac, which will contain the spores. Between the wall of the capsule, which is composed of several layers of cells, and the spore-sac is a wide intercellular space (h) bridged across by trabeculae consisting of rows of chlorophyll-containing cells. At the junction of the operculum (d) with the rest of the capsule is a circle of cells forming the annulus (a), by help of which the operculum is detached at maturity as a small lid. Its removal does not, however, leave the mouth of the capsule wide open, for around the margin are two circles of pointed teeth forming the peristome. These are the thickened cell-walls of a definite layer of cells (p), and appear [v.04 p.0651] as separate teeth owing to the breaking down of the unthickened cell-walls. The numerous spores which have been developed in the spore sac can thus only escape from the pendulous capsule through narrow slits between the teeth, and these are closed in damp air. The unicellular spores when supplied with moisture germinate (fig. 12) and give rise to the sexual generation. A filamentous protonema is first developed, some of the branches of which are exposed to the light and contain abundant chlorophyll, while others penetrate the substratum as brown or colourless rhizoids. The moss-plants arise from single projecting cells, and numerous plants may spring from the protonema developed from a single spore.



The majority of the mosses belong to the same great group as Funaria, the Bryales. The other two subdivisions of the Musci are each represented by a single genus. In the Andreaeales the columella does not extend to the upper end of the capsule, and the latter opens by a number of lateral slits. The Sphagnales also have a dome-shaped spore-sac continued over the columella, and, though their capsule opens by an operculum, they differ widely from other mosses in the development of the sporogonium as well as in the characters of the sexual generation. The three groups are described separately below, but some more general features of the mosses may be considered here.

On the whole mosses grow in drier situations than the liverworts, and the arrangements they present for the conduction of water in the plant are also more complete and suggest in some cases comparisons with the higher plants. In spite of this, however, they are in great part dependent on the absorption of water through the general surface of the shoot, and the power of rapid imbibition possessed by their cell-walls, the crowded position of the small leaves on the stem, and special adaptations for the retention of water on the surface, have the same significance as in the foliose liverworts. The different appearance of exposed mosses in dry weather and after a shower illustrates this relation to the water supply. The protonema is always a well-marked stage in the life-history. Not only does a moss-plant never arise directly from the spore, but in all cases of vegetative reproduction, apart from the separation of branches by decay of older regions of the plant, a protonema is found. Usually the protonema is filamentous and ceases to be evident after the plants have developed. But in some small mosses (e.g. Ephemerum) it plays the chief part in assimilation and lives on from year to year. In Sphagnum, Andreaea and some genera of the Bryales the protonema or some of its branches have the form of flat plates or masses of cells. The formation of the moss-plant on the protonema is always from a single cell and is similar in all mosses. The first three walls in this cell intersect one another, and define the three-sided pyramidal apical cell by means of which the shoot continues to grow. In Fissidens and a few other mosses the apical cell is two-sided. The leaves formed by the successive segments gradually attain their normal size and structure. Each segment of the initial cell gives rise to a leaf and a portion of the stem; the branches arise from the lower portion of a segment and stand immediately below a leaf. The leaves may form three vertical rows, but usually their arrangement, owing to the direction of the segment walls at the apex, becomes more complicated. Their growth proceeds by means of a two-sided apical cell, and the midrib does not become more than one cell thick until later. In addition to the leaves the stem often bears hair-like structures of different kinds, some of which correspond to modified branches of protonema. The branched filamentous rhizoids which spring from the lower region of the stem also correspond to protonemal branches. The structure of both stem and leaf reaches a high grade of organization in some mosses. Not only are thick-walled sclerenchymatous cells developed to give rigidity to the periphery of the stem and the midrib of the leaf, but in many cases a special water-conducting tissue, consisting of elongated cells, the end walls of which are thin and oblique, forms a definite central strand in the stem. In the forms in which it is most highly developed (Polytrichaceae) this tissue, which is comparable with the xylem of higher plants, is surrounded by a zone of tissue physiologically comparable to phloem, and in the rhizome may be limited by an endodermis. The conducting strands in the leaves show the same tissues as in the central strand of the stem, and in the Polytrichaceae and some other mosses are in continuity with it. The independent origin of this conducting system is of great interest for comparison with the vascular system of the sporophyte of the higher plants.

The sexual organs, with the exception of the antheridia of Sphagnum, are borne at the apices of the main shoot or of branches. Their general similarity to the mature antheridia and archegonia of liverworts and the main difference in their development have been referred to. The antheridia open by means of a cap cell or groups of cells with mucilaginous contents. The details of construction of the sporogonium are referred to below. In all cases (except Archidium) a columella is present, and all the cells derived from the archesporium produce spores, no elaters being formed. In a few cases the germination of the spore commences within the capsule. The development of the sporogonium proceeds in all cases (except in Sphagnum) by means of an apical cell cutting off two rows of segments. The first periclinal division in the region forming the capsule separates an inner group of cells (the endothecium) form the peripheral layer (amphithecium). In Sphagnum, as in Anthoceros, the archesporium is derived from the amphithecium; in all other mosses it is the outermost layer of the endothecium.

Vegetative propagation is widely spread in the mosses, and, as mentioned above, a protonema is always formed in the development of the new plant. The social growth of the plants characteristic of many mosses is a result of the formation of numerous plants on the original protonema and on developments from the rhizoids. Besides this, gemmae may be formed on the protonema, on the leaves or at the apex, and some mosses have specialized shoots for their better protection or distribution. Thus in Georgia the stalked, multicellular gemmae are borne at the ends of shoots surrounded by a rosette of larger leaves, and in Aulacomnium androgynum they are raised on an elongated leafless region of the shoot. In other cases detached leaves or shoots may give rise to new plants, and when a moss is artificially divided almost any fragment may serve for reproduction.

Even in those rare cases in which the sexual generation can be developed without the intervention of spore production from the tissues of the sporogonium, a protonema is formed from cut pieces of the seta or in some cases from intact sporogonia still attached to the plant. This phenomenon of apospory was first discovered in mosses, but is now also known in a number of ferns (see PTERIDOPHYTA).



Sphagnales.—The single genus Sphagnum occupies a very distinct and isolated position among mosses. The numerous species, which are familiar as the bog-mosses, are so similar that minute structural characters have to be relied on in their identification. The plants occur in large patches of a pale green or reddish colour on moors, and, when filling up small lakes or pools, may attain a length of some feet. Their growth has played a large part in the formation of peat. The species are distributed in temperate and arctic climates, but in the tropics only occur at high levels. The protonema forms a flat, lobed, thalloid structure attached to the soil by rhizoids, and the plants arise from marginal cells. The main shoot bears numerous branches which appear to stand in whorls; some of them bend down and become applied to the surface of the main axis. The structure of the stem and leaves is peculiar. The former shows on cross-section a thin-walled central tissue surrounded by a zone of thick-walled cells. Outside this come one to five layers of large clear cells, which when mature are dead and empty; their walls are strengthened with a spiral thickening and perforated with round pores. They serve to absorb and conduct water by capillarity. The leaves have no midrib and similar empty cells occur regularly among the narrow chlorophyll-containing cells, which thus appear as a green network. The antheridia are globular and have long stalks. They stand by the side of leaves of special club-shaped branches. The archegonial groups occupy the apices of short branches (fig. 13, A.). The mature sporogonium consists of a wide foot separated by a constriction from the globular capsule (B). There is no distinct seta, but the capsule is raised on a leafless outgrowth of the end of the branch called a pseudopodium (C, qs). The capsule, the wall of which bears rudimentary stomata, has a small operculum but no peristome. There is a short, wide columella, over which the dome-shaped spore-sac extends, and no air-space is present between the spore-sac and the wall. In the embryo a number of tiers of cells are first formed. The lower tiers [v.04 p.0652] form the foot, while in the upper part the first divisions mark off the columella, around which the archesporium, derived from the amphithecium, extends. The sporogonium when nearly mature bursts the calyptra irregularly. The capsule opens explosively in dry weather, the operculum and spores being thrown to a distance. The spore on germination forms a short filament which soon broadens out into the thalloid protonema. Some twelve species of Sphagnum are found in Britain.