SCIENTIFIC AMERICAN SUPPLEMENT NO. 841



NEW YORK, FEBRUARY 13, 1892

Scientific American Supplement. Vol. XXXIII, No. 841.

Scientific American established 1845

Scientific American Supplement, $5 a year.

Scientific American and Supplement, $7 a year.

* * * * *



TABLE OF CONTENTS.

I. ANTHROPOLOGY.—Investigation of a Mound near Jefferson City, Mo.—By A.S. LOGAN.—Prehistoric remains from the banks of the Missouri River II. BIOLOGY.—New Observations on the Language of Animals.—By M. DE LACAZE DUTHIERS.—A lengthy examination of some facts in the language of animals, including birds and quadrupeds

III. BOTANY.—Electricity in Agriculture.—By CLARENCE D. WARNER.—The effect of currents of electricity upon the germination of seeds. —Interesting experiments detailed, which can be easily repeated

Electricity in Horticulture.—The effect of the electric light on vegetation, availability it may possess for the gardener

Pentapterygium Serpens.—A Himalayan flowering plant introduced in England about ten years ago.—2 illustrations

The Perforation of Flowers.—What insects do to promote the propagation of plants by perforating the flowers in search of honey.—16 illustrations

IV. CHEMISTRY.—A New Laboratory Process for Preparing Hydrobromic Acid.—By G.S. NEWTH.—Simple synthesis of hydrogen and bromium

Boron Salts.—Boron sulphides and selenides and silicon selenide

Detection of Peanut Oil in Olive Oil.—A practical laboratory test for the above adulteration

Hydroxylamine.—Recent preparation of this compound and its properties

New Boron Compounds.—Compounds of boron, phosphorus, and iodine recently prepared by M. MOISSAN

Sapotin, a New Glucoside.—By GUSTAVE MICHAUD.—Preparation of a new glucoside from almonds and other sources

V. CIVIL ENGINEERING.—Completion of the Mersey Tunnel Railway.—The penetration of the bed of the Mersey River by a tunnel at the rate of 150 feet per week.—Details of the work

VI. EDUCATIONAL SCIENCE.—Chinese Competitive Examinations. —Interesting details of the famous examinations of China.—Fatal consequences to overworked competitors

VII. ELECTRICAL ENGINEERING.—High Speed Engine and Dynamo.—A high speed compound engine, running at 500 revolutions per minute, with direct-driven dynamo for electric lighting.—3 illustrations

VIII. MEDICINE.—The Treatment of Rattlesnake Bite by Permanganate of Potassium, Based on Nine Successful Cases.—By AMOS W. BARBER, M.D.—The use of this powerful disinfectant, and the proper treatment and mode of applying it.

IX. METEOROLOGY.—Modification of Our Climate.—By JOSEPH WALLACE.—Climate epochs and the probabilities of the present climatic era.—Changes within the records of man

The Eruption of Krakatoa.—A graphic description of this catastrophe, involving the lives of 35,000 people

X. MILITARY ENGINEERING.—The Military Engineer and His Work.—By Col. W.R. KING.—A Sibley College lecture, treating of the special problems In fortifications, sieges, and the more pacific work of surveys and explorations

XI. MINERALOGY.—Natural Sulphide of Gold.—By T.W.T. ATHERTON.—A probable new occurrence of gold

XII. NATURAL HISTORY.—The Living Jerboa in the Zoological Garden of Berlin.—A rare rodent from South Africa, one seldom seen alive in captivity.—5 illustrations

XIII. NAVAL ENGINEERING.—Twenty-four Knot Steamers.—The possibility of fast ships for long voyages.—The prospects and difficulties

XIV. RAILROAD ENGINEERING.—A Steam Street Railway Motor.—A noiseless motor built of steel on trial in Chicago.—1 illustration

XV. SANITARY ENGINEERING.—Some Means of Purifying Water.—Different filtering processes and the subsidence treatment of water

XVI. TECHNOLOGY.—Action of Caustic Soda on Wood.—By M.H. TAUSS.—Direct experiments on the action of lye on wood at various pressures

Burning Brick with Crude Oil Fuel.—The use of petroleum in brick kilns.—Its advantages, cleanliness, and cheapness.

Chlorine Gas and Soda by the Electrolytic Process.—The decomposition of common salt solution into chlorine and caustic soda on the commercial scale

How Enameled Letters are Made.—The manufacture of separate enameled letters as conducted in London.—5 illustrations

How Mechanical Rubber Goods are Made.—Hose, corrugated matting, packing, and jar rings.—Processes of their production

* * * * *



THE LIVING JERBOA IN THE ZOOLOGICAL GARDEN OF BERLIN.

Like other strangely formed quadrupeds, the jerboas are counted among the curiosities of the animal kingdom, and as such are described in natural history; but, nevertheless, there has never been a good exhibition of them, for the simple reason that live jerboas are seldom seen in Europe, as they usually die during the journey hither or soon after their arrival. After some hesitation I decided to purchase a pair that I happened to find mentioned in the price list of Mr. C. Reiche, of Alfeld, as one of the most interesting specimens obtained during his expedition to South Africa the year before; but I, also, found the sensitiveness and delicacy of the jerboa very trying, for the short journey from Alfeld to this city caused the death of the female and reduced her mate to such a condition that when it arrived there seemed little hope that it could ever be utilized for scientific research or artistic life studies.



My anticipation and pleasure were changed to vexation and grief. The most careful nursing—the stiff, weak little legs were dipped into and rubbed with French brandy—and a warm pen with a dry sanded floor directly over a heater, did their work. As the new-comer got on his feet again my hope gained new life, and now our jerboa is my delight. It is, indeed, a curious animal. One who saw it only in the day time asleep would scarcely know what he had before him, for he would see little more than a mass of soft, bright sandy hair. The coming of the keeper with the dish of food and the unfastening of the door of the cage bring life to the ball of hair in the corner; a part of it is unrolled and the long, black-tipped tail with two lines of hair is laid out on the ground, and then on each side of it a leg is run out which is nearly as long as the tail and is provided with blunt, smooth, hoof-life nails; and, finally, the head and body are distinguishable and the animal stretches out comfortably on its back in the sand. The fine-skinned, hairless ears still hang limp, the eyes are half closed and the short fore legs are crossed under the chin.

But now the animal gets on its legs by an elastic swing, and its ears are raised and its eyes wide open, so that we can see that the latter are large and dark, with long eyelashes. Then the jerboa raises himself to his full height and playfully measures his cage by one bound from corner to corner. Soon after, the fresh food receives due attention, the animal either jumping toward it in rabbit fashion or crawling slowly on all fours. When it has reached its goal it again assumes the upright position, in which it is evidently most comfortable, and begins to eat it in his own peculiar way; that is, sitting on his hind legs he quickly seizes a piece of bread, turnip or other food in his fore paws and conveys it to his mouth, apparently indifferent to the nature of the food before him. He never takes anything directly in his mouth; even the grass on a piece of turf that I had given to him as an experiment was not eaten as it would have been eaten by other animals, but was first plucked with the fore paws. If we notice the position of the mouth, far back on the under side of the head, we will understand that the jerboa could not take his food in any other way. Besides this, nothing of special interest has been observed in this nocturnal creature, but he, of course, lives more regularly and quietly than if his mate had lived.

One who knows anything about the structure of animals' bodies need not be told that the jerboa is a rodent. One glance at the peculiar shape of his head would assure him of that. The form of the rest of its body, especially its long hind and short fore legs, give unmistakable proof that it is related to the jumping rodents; it belongs, in a wide sense, to the family of the jumping mouse, the scientific name (Dipodidea, two-footed) of which is very significant, as the very short fore legs are usually carried close under the chin and are scarcely noticeable when the animal is in its normal position, and are of little use when it moves about. The hind legs are very strong, and when going at full speed the jerboa takes jumps that measure from eight to ten yards, according to the unanimous testimony of various witnesses.

The jumping mouse of North America, which is somewhat larger than an ordinary mouse, is, according to Brehm, also as swift as an arrow or a low-flying bird. This exceptional velocity is not all that reminds us of a bird, for there is also a strong resemblance in the formation of certain parts of the bodies of the two creatures; but, after consideration, this should not seem strange, because in animal organisms similar means are employed to accomplish similar ends. It is only natural that there should be peculiarities in the construction of the limbs and skulls of the Dipodidea with their bird-like movements and bird-like sharp-sightedness, that are usually found only among birds. The consistency between the construction of their bodies and their mode of life is a beautiful example of fitness; only by extraordinary quickness of movement and sagacity could the little defenseless plant-eaters maintain the struggle for existence in the barren steppes and deserts. The formation of the bodies of the different members of the family varies according to their needs. The jerboa is the largest member of the family. Very little is known of his life when free; it being known only that the jerboas are widely spread over the whole of southern Africa, and are nocturnal burrowers of the steppes. During the rainy season they remain in a sort of winter sleep.—Dr. L. Heck, in the Illustrirte Zeitung.

* * * * *



NEW OBSERVATIONS ON THE LANGUAGE OF ANIMALS.

By M. DE LACAZE DUTHIERS, of the Institute of France.

I had occasion in a note published several years ago in the Revue Scientifique to mention a parroquet which I have since continued to observe, the manifestations of whose intelligence are both interesting and instructive. Many acts of birds are difficult of interpretation. To speak only of their songs, the meanings of most of the innumerable varieties of sounds which they produce, and of their diverse warblings, escape us completely. It is not possible to find the meaning of these things except by forming suppositions and hypotheses, or by catching the connections between cries and acts. But instances of the latter kind are extremely rare in comparison with the great majority of the manifestations made by animals.

Thus, to select examples which every one can observe, when a canary bird is warbling in its cage and becomes deafening, or when a lark rises straight up in the air and incantat suum tirile tirile—sings its tirile tirile—as Linnaeus picturesquely expresses it; when a tomtit, leaping from branch to branch of a willow or among the reeds, repeats its florid warblings; when a raven croaks; when a blackbird whistles—what significance can we attach to their songs and their cries? Certainty is impossible, and we can only form more or less plausible hypotheses concerning the interpretation of them.

The parrot furnishes us one more aid in this matter than other birds, and this helps us, to a certain extent, in overcoming the difficulty of interpretation. It has an articulate voice, and when we have taught it a few words, the meaning which it gives them may be better divined by us according to the tone and the rapidity or slowness of its utterance. This permits us to discover the feelings that move it, for we can better judge from an articulate sound than from one that is merely musical.

Much has been written on the language of animals. It is neither my desire nor my intention to repeat here all that may have been said on this subject. It would take too long and would be of no use. I have often witnessed facts that may be of interest to those who are occupied with the mental manifestations of animals. I will simply relate them; and of such as are already known, I will merely mention them anew, admitting in advance a priority for others which I do not demand for myself.

There can be no doubt that animals communicate their impressions by an inarticulate voice. Common sense and the most superficial observations are opposed to the negative of this proposition. But when a canary bird warbles till it stuns us, or a nightingale sings in the shadows on the fine nights of June, can we follow and discover the significance of those modulations—now sharply cadenced, now slowly drawn out, and ending with a trill long and accurate enough to challenge the most skillful musician?

All the poets of every country have constantly sung of the songs of Philomela. But their fervent and enthusiastic verses cast little light on the value of the nightingale's song. It is said that the male sings for the entertainment of the sitting female, but there is no proof of the assertion. The note warning of the approach of danger is easier to recognize. The bird utters a short, hoarse cry, and repeats it with a succession of trrre, trrre, which is impossible to mistake. When we hear this cry we may be sure that an enemy is near. Music gives way to a cry of distress and warning, and the female leaves her nest if the sounds become piercing. What do we know of the gobbling of the turkey, which the whistling and the cries of children excite? They are doubtless responses to those challenges; but what do they mean?

The crowing of the cock, recurring regularly at fixed hours, has some signification, but we cannot comprehend it. If on a fine afternoon in autumn the cock crows, and repeats his strain between two and four o'clock, the countrymen in some places will say there will be a fog on the morrow, and they are generally not mistaken. Hens do not mistake his notes either; when a leader of the troop, coming upon a spot rich in food, utters his peculiar chuckle, they run from all around to share the find with him. It is evident that the cock has called them and they have understood him. These facts indicate that there is some definite sense in this inarticulate language; and examples of it, taken from other groups, might be multiplied.

The dog, intelligent animal as he is, manifests his affection on meeting his master, with peculiar cries which vary with the intensity of his joy. No one could confound these notes of pleasure with those which he utters when he is angrily driving away a beggar, or when he meets another dog of unpleasant appearance and puts himself in the position of attack.

An interesting study of the voice of the dog on guard may be made in the country at night. If another dog barks in the distance, the house dog answers in a peculiar manner. He gives a few growls, stops, seems to listen, begins again, very often getting answers; and, after two or three interruptions, he terminates his barking with abrupt yelps, loud at the beginning and long drawn out, and gradually dying away. This ending of his cries is habitually accompanied by his raising his head and throwing it back. I have often, when within the house, on hearing the watch dog bark in this way, opened the window to assure myself on the subject, and distinguished, as I could not do with the windows closed, the voice of another watch dog barking in the same way in the distance—the barkings of the two dogs alternating, one answering the other. There is in such cases an evident communication of impressions. One of the dogs, having had his attention aroused by some unusual noise, has transmitted his impression to the other, as sentinels posted at intervals call out theft warnings one to another. I have often repeated this observation during the long evenings of winter.

Another example, little known in thickly populated countries, is drawn from a curious scene which I witnessed during a winter passed in Perigord Noir. We had remarked that for several nights the three watch dogs, a young and an old male and a bitch, howled often toward midnight, but in a peculiar way. One night in particular, during their tedious concert, just as we had got to sleep, they mingled with their cries howlings like those they would have uttered if they had been beaten, with a shading hard to define, but which we perceived plainly; and we remarked that, leaving their kennel in the avenue that led up to the lodge, they had come to close quarters with one another at the gate, with alternating howlings and plaintive cries. Inquiring in the morning for the cause of these singular cries, the peasants told me that a wolf had passed, and predicted that it would return. They said, too, that a neighbor's hunting bitch had disappeared, and its bones had been found in the fields near a wood. We were awakened again about midnight by the cries of the dogs, and the scene was renewed. Informed as we now were of the nature of what was going on, we ran to one of the windows, whence we could see, in the clear light of the moon, all that passed. The three dogs were cowering against the gate, the oldest one howling by the side of the others, while the younger one and the bitch were exposed at intervals to the attacks of another animal, browner than they, and of about their size, without defending themselves, but moaning as if they were undergoing a vigorous correction.

Frightened, doubtless, by the opening of the blinds of the first story above him, the strange animal had gone away and was sitting in the middle of the road. We could only see that he had straight ears. While we were going down to get a gun the visitor came back to his charge on the dogs, which had begun howling after he left them, and resumed the cries significant of chastisement when they were attacked again. For some reason, perhaps because he heard the click of the gun, the foe drew back and sat down in a garden walk, concealed by a bunch of shrubbery. The three dogs, notwithstanding our reiterated urging, were no more disposed to pursue him than before. If the assailant had been a dog they would have rushed upon him, but they stayed cowering at the gate and howled distressfully. The bitch was most affected, and they all seemed paralyzed by fear. It is said in the country that bitches are especially liable to be attacked by wolves. It was so here. The most certain feature in the matter was the terror of the animals. They were capable of resisting the attack three times over. The young dog was a savage one, and passers-by were afraid of the bitch; but that night they were terrorized, and all incapable of defending themselves. Their cries were therefore due to the same cause as in the preceding night—the presence and attacks of the wolf. I could not have realized their meaning if I had not been a witness of the scene—that is, I could not have correlated the cries and the acts.

A shot at the animal behind the bushes was followed by a hoarse cry. He was hit, and ran; but, in spite of our urgings, the dogs stayed at the gate and only stopped howling. Under any other conditions, upon the signal of the shot they would all have started in pursuit of the wounded animal.

A wolf came to the farm during the last winter (1890-91) and attacked the same bitch. He would have carried her off, for he had seized her by the throat, if we could judge from the stifled cries she uttered; but this time he found with her a new watch dog—a mountain bitch from the Pyrenees—of a breed that attacks the wolf and the bear. The wolf would have been caught if he had not run away. He did not return, for he had been attacked, and learned what he had to deal with.

The Pyrenean breed furnishes excellent watch dogs. I knew one of remarkable traits. At evening he would go round the house, giving two or three growls at each door. With his head raised he seemed to listen to his fine voice, then he would start again and go to another door. He seemed desirous to show those who were observing him that he was attending to his post as guardian. He then went away in silence along the walk, through a dark, rising hedgerow, leaping the slight hillock, yelping toward the wood. He listened, yelped again, and went in. There was never any failure in this performance, but every evening as night was coming on he began his round, which no one had taught him. It was all done in his function as a guard. It would be hard to determine what his yelps meant, but there were in them an inflection, a sonorousness, and a continuance quite different from those he uttered when pursuing a passer-by or when going to meet a person coming toward the house. Every one who has a watch dog is able to tell by the sound of his barking when a person is coming up, and usually what sort of a visitor it is.

The peasants' dogs of the southwest of France dislike the country millers, because of the long whips which they are always carrying and snapping, and with which the dogs, running after them, are often struck. From as far off as the snapping of the whip can be heard, the dogs come to wait for the millers and pursue them; and it is easy to recognize when the millers are passing, by the behavior of the dogs. There is in this also a significance, at once aggressive and defensive, in the cries which one can, by giving a little attention, soon learn to distinguish.

Another example of the reality of the various meanings of the cries of the dog under different circumstances is afforded by the companies that collect around a female in heat.

I have a very intelligent and experienced brach hound, the same which with the bitch had to face the attack of the wolf. He amuses me much at my country lunches. Hunting dogs which have been much with their masters at lunch do not like to have the drinking glass offered them. This dog was much afraid of the glass, and I had only to present it to him at lunch time to make him keep his distance. I used to keep my door open at lunch, for the amusement of observing how I could make him stop exactly at the threshold without stepping over it. If he had passed over it I could always send him back by casting toward him a few drops of water from the bottom of the glass after drinking. Sitting, as was his habit, on the sill of the door, with the tip of his muzzle never extending beyond the plane of the panels, he would follow my motions with the closest attention, reminding me, if I failed to give him a sign of attention, by a discreet, plaintive cry, that he was there. But if I touched my glass, he would spring up at once; if I filled it, he would put himself on guard, utter a kind of sigh, sneeze, lick his lips, yawn, and, shaking his ears briskly, make little stifled cries. Then he would grow impatient, and more and more watchful and nervous. When I lifted my glass to my lips he would draw back, working gradually nearer to the farther door, and at last disappear and hide. One who was looking at him without seeing me could tell by his wails and his attitude the level and position of my glass. When the glass was horizontal, I could see only about half of his head, with one eye regarding me fixedly, for that was usually the critical moment—the one, also, when the wails and restraints were most demonstrative of the anxious fear of my poor animal.

When we dine in the kitchen, which is on the ground floor, the dogs are usually all put out. There are four of them, three young and not experienced, and this old, sagacious brach hound. He insists on coming in, and, to gain his purpose, tries to have the door opened. Although no person may be coming up the walk, he dashes down it barking, all the others going along too and yelping with him; then he stops, remains a little behind after having got the others out of the way, and, turning his head from moment to moment, looks to see if the door has been opened, for we generally go to it to see who has come. In that case the feigned attack is successful, and the dog, who has evidently meant to give the alarm so as to have the door opened, comes in at once and claims a place at the table. He has accomplished his end, for the door is usually shut without paying attention to his having got in. I have frequently witnessed this stratagem, and when, during my kitchen dinner, I suddenly hear the dogs yelping after the brach hound has begun, I am pretty sure that nobody is in sight.

I have forgotten where I found the next story of an old dog who was also very sagacious. Hunting dogs, when they grow old, become rheumatic, or are at least debilitated with pains. We know, too, that they crave heat, and get as near the fire as possible—a craving which increases as they grow older. One such dog, older than the others, and slower in getting into the lodge on returning from the hunt, was often crowded away from the fire by the other livelier dogs getting all the best places before him. Finding himself thus turned out in the cold, he would dash toward the door barking, when the others, supposing it was an alarm, would rush away too, while the old rheumatic went to the fire and selected a place to suit him.

It is not necessary to dwell upon the intelligence shown by such acts. But it is hardly contestable that the old animal, who knows how to play such tricks upon his less experienced companions, deceives them by his intonations, while he is well aware that no enemy is approaching the house; but he does it scientifically, by the inflections of his voice, as a man speaking to other men would do in announcing the arrival of an imaginary enemy.

Inarticulate cries are all pretty much the same to us; their inflections, duration, pitch, abruptness, and prolongation alone can inform us of their purpose. But experience and close attention have shown us the connection of these variations with the acts that accompany or precede them. Animals evidently understand these inflections at once. We cannot better compare the language of animals than with what takes place in a pleasant sport, a kind of pantomime of the voice or language which many youth doubtless understand, and which I venture to refer to here to aid in more easily conceiving of the communication of thought among animals by sounds which seem to us all alike. When I was engaged in hospitals, the evenings in the guard room were sometimes enlivened by the presence of a companion who excelled in humorous mimicry. He would represent a man in liquor who had stopped at a fountain that flowed with a gentle sound, somewhat like that of his own hiccough. A single oath, pronounced in different tones, was sufficient to enable us to comprehend all the impressions, all the states of mind through which this devotee of Bacchus passed. The oath, at first pronounced slowly and with an accent expressing relief, represented a feeling of satisfaction, with shadings of prolonged exclamation which it would be hard for one to imagine without suggestion. The continued flowing of the fountain made our drunken man impatient, and he wanted it to stop. This state of mind was translated by a new modulation of the same word. In a little while the gurgling of the fountain produced astonishment. Was it possible that he, with all the liquid he had imbibed, could vomit so much and for so long a time? This mental condition was expressed by a new modulation of the same oath. The first movement of surprise over, resignation follows, and our man decides to wait patiently for the end. A period of half lethargy was easily represented by the slowness and weakness of the man's voice while living up to this decision; but when he comes out of this sleepy condition and hears the fountain again, he is possessed with fear; he cannot understand the flood he is pouring out—he dares not move—he believes he is lost. Gradually the fumes of the liquor pass away, and, his mistake being recognized, the drunkard is taken with a laughing and a gayety which are indicated by the same oath repeated in tones corresponding with the satisfaction he is then enjoying. This making the series of impressions a man passes through comprehensible by a single word, varied in pronunciation and utterance, is very like the language of animals, which is always the same, and the significance of which is given by variety of intonations corresponding with sensational conditions.

The mewing of the cat is always the same; but what a number of mental conditions it expresses! I had a kitten whose gambols and liveliness entertained me greatly. I understood well, when it came up to me mewing, what the sound meant; sometimes the kitten wanted to come up and sleep in my lap; at other times it was asking me to play with it. When, at my meals, it jumped on my knees, turned round, looked at me, and spoke in a coaxing and flattering way, it was asking for something to eat. When its mother came up with a mouse in her jaws, her muffled and low-toned mew informed the little one from a distance, and caused it to spring and run up to the game that was brought to it. The cry is always the same, but varied in the strength of the inflections and in its protraction, so as to represent the various states of mind with which my young animal is moved—just as it was with the drunken man in the mimicry scene. These facts are probably well known to all observers of animals.

We have seen that this tonality of the watch dog's cries is competent to indicate that a person is coming to the house. We find similar cries of warning uttered by birds. When I was a professor in the faculty of Lille, I frequently visited the well known aged Professor of Physics, M. Delezenne. He had a working room at the end of a garden, in which a laughing mew wandered. From the time that any one came in till he went out, this bird made the vocal explosions to which it owes its name; and the good professor was certain, without ever being mistaken, that somebody was coming to his laboratory. He was notified. My Jaco in Paris has a warble that answers the ringing of the bell. If we have not heard the bell, we are notified by Jaco of its ringing, and, going to the door, find some one there. I have been told of a parrot belonging to the steward of a lyceum which had heard the words "Come in," when any one rang the bell. He never failed to cry, "Come in," when the bell moved, and the visitor was embarrassed at seeing nobody after having been invited to open the door.

Instances in which the cries of birds had an incontestable and precise signification are numerous; let me refer to a few of the best known. The cackle of a hen, after having laid an egg and left her nest, is decidedly characteristic. Her clucking when she is impelled to sit on her eggs, or when she is calling her chicks, is no less demonstrative. There is not a farmer who does not recognize it and understand it. In these things we see the relation between the tone of the prating or cluck of the hen and her acts. But when a nightingale sings all night, or a goldfinch whistles, or a raven croaks, we cannot so easily interpret the significance of their inarticulate sounds. The finch calls its mate by uttering a few notes followed by a long trill. Matches of a barbarous character, based on this habit, I were held in the north of France while I was living at Lille, between 1855 and 1860. I do not know whether they have been suppressed or not, but the laws for the protection of animals ought to take cognizance of them. The gamesters put out the eyes of the male finches, and made them, thus blinded, compete as singers, for which purpose they brought their cages into proximity. When the birds heard and recognized one another's voices, they made their appeal to the female; the one that renewed his amorous trills most frequently, protracted them longest and to the last, gained the prize. The bird that was declared victor received a medal amid the applause of a large and enthusiastic crowd; and considerable wagers were staked upon the result. I have heard that these poor blinded birds sometimes fell down exhausted with singing, and kept on calling the absent female till they died, not being willing to yield to a rival, who on his side was also keeping up his equally useless appeals.

These finch contests were suggested after the meaning of the song of the birds was learned. But when these birds, which are more usually isolated—whence they have been named Fringilla coelebs, or celibates—hop around our houses and also utter their amorous trills at another than the mating season, they are evidently not calling the female. Should we not then seek to determine by the tone whether their call, which is always the same, is amorous or not?

In countries where flocks of turkeys are raised one can learn very quickly from their gobblings when they have captured a hare. If they meet him standing still or lying down, they form in a circle around him, and, putting their heads down, repeat continually their peculiar cries. The hare remains quiet, and it is sometimes possible to take him up, terrorized as he is in the midst of the black circle of gobbling beaks and heads. The language of the turkeys is at that time incontestably significant. It is warlike, and similar to that of the males when they are fighting. In the present instance they have joined for war, and they make it on the frightened hare.

My Jaco, like all parrots, which are excellent imitators, pronounces a few words and repeats them over and over again. Such birds amuse us because the words they know sometimes happen to be ludicrously fitting. A bird of this kind had been struck by the note sounded by the wind blowing into a room through a crack in the glass work whenever a certain door was opened; and he had become so perfect in his imitation that they sometimes, on hearing the noise, went to shut the door when it was not open.

Jaco formerly belonged to a very pious old lady who was accustomed to say her litanies with another person. He had caught the words "Pray for us," in the invocations to the several saints, and said them so well as sometimes to deceive his learned mistress, and cause her to think she was saying her litanies with two colleagues. When Jaco was out of food, and any one passed by him, he would say, "My poor Cocotte!" or "My poor rat!" in an arch, mawkish, protracted tone that indicated very clearly what he wanted, and that his drinking cup was empty. There was no doubt in the house as to his meaning; and whenever one heard it he said: "He has nothing to eat." He was exceedingly fond of fresh pits of apples and pears, and I was in the habit of collecting them and keeping them to give him. So whenever, as I came near him, I put my hand into my pocket he never failed to say: "Poor Cocco!" in a supplicating tone which it was impossible to mistake. A sugar plum is a choice morsel to him. He can tell what it is from a distance when I hold it out in my fingers; and when I give it to him he cannot restrain himself if it has been any considerable time since he has had the delicacy. Usually, after having made the first motion to get it, as if he were ravished and wanted to express his joy in advance, he would draw back before taking it, and say, in a comical tone, "Hold, my poor Cocotte!" His manner of thanking in advance is likewise amusing. The expression of his eyes and the pose of his head are all in accord with the tone of his exclamation. When he tastes the plum he utters a series of ahs, and produces a kind of warble by prolonging some of his notes and shortening up others. We find in these examples, without doubt, that the articulate voice makes us better able to judge the meaning of the impressions that are moving the animal than inarticulate cries, or merely musical sounds. When Jaco met a child for whom he had a great affection, he would promenade on his perch, or turn the wheel, spreading out his tail and ruffling the feathers of his head, while his eyes grew red with excitement if the child was too slow in bestowing the accustomed caress. Then he would stop, bend down his head, and, looking at his friend, say pleasantly, "Jaco," in a tone and with a manner quite in contrast with the pronunciation of the same word when he was hungry.

It is not the word he speaks that is of interest; he might have been taught another, and it would have been the same; but it is the tone. In this case, too, the articulation gives an easier clew to the meaning the bird seeks to express, having a meaning according to the manner of pronouncing it, than any isolated, simply musical sound, like the song of the nightingale, canary bird, and warbler. This became evident to me, not from observing animals for a few moments without seeing them again, but from studying them continuously.

Jaco did not like solitude, and was talkative and fond of being caressed, like all of his kind. One day, when there was no one in the country house, all having gone out into the garden or the fields, I heard him saying over what few words he knew, in different inflections. I went quietly into the room where he was, without being seen; but he heard my steps, although I walked in very cautiously, hoping to surprise him. He ceased his chatter, listened, and, after a silence, pronounced "Jaco" in a low tone, drawing out the end of the word. He listened again, and repeated the word in the same tone; then, after another silence, repeated it with a rise of the voice. I continued observing him, and, as he heard no one, he raised his tone gradually, repeating the same word, and ended at last with a genuine cry of distress. The people ran in from without, supposing something had happened to him. He then repeated his name in a lower tone, which seemed to indicate his satisfaction at finding his isolation ended. I went in myself, and his prattle unmistakably betrayed his gladness at being no longer alone.

Is there not in this an act of real intelligence? While alone, the parrot entertained himself by talking; but when he heard a sound he hoped at first to see some one come; and when no one answered him, he raised his voice, as a person would do who calls, and, getting no reply, cried out louder and louder till he was heard and answered. The meaning of the differences of intonation is as evident in this case as in that of the drunken man. A parrot raised in the South had learned to swear in the local patois. Being fond of coffee, he was sometimes given a spoonful, which he would come awkwardly up to the table to drink with his master. One day the master, not thinking of his bird, had already added cognac to his coffee, and gave the parrot the accustomed spoonful. The parrot took a swallow of it, and, in his surprise at the novel taste, raised his head and repeated the oath in a tone that excited laughter in all who were present. The cause of his surprise being discovered, he was soothed, and then took his usual ration with evident signs of contentment. The mimicry of language in this case clearly represented the shade of the new impression he felt.

Jaco is very timid. In the evening, when he is put to roost in a close and dark room, he is afraid of the shadow of his perch that is cast by the light we carry in our hand; he eyes it, and utters a low cry, which stops when the candle is blown out and he cannot see the shadow any longer. He stands in dread of blows in the bottom of his cage, because, having a wing broken, he cannot fly, and is afraid of falling. Feeling his weakness, his language has a different tone from the usual one. Large birds flying in the sky above him annoy him greatly, and we can all tell by his voice when such a bird is near or flying over. He inclines his head and chatters in a low tone as long as the bird is in sight, paying no attention to anything else. Turkeys and hens announce the approach of a bird of prey in a similar manner.

We find in the facts which we have related, as well as in many others which are cited respecting the ways and habits of parrots, proofs of a remarkable intelligence. These creatures are distinguished by the unlimited affection which they bestow upon some persons, as well as by their excessive dislikes, which nothing can explain. Jaco conceived an extraordinary dislike for a maid who, although she took good care of him, was in the habit of washing the bottom of his cage under a faucet. He afterward discarded another person, whom he had liked so much that she could do what she pleased with him, even to passing her hand over his back and taking him by the tail, holding him in her hands, or putting him in her apron—caresses of a kind that parrots do not usually permit. Nothing astonished him or offended him. He proved very inconstant toward her, and now, while better disposed toward the other girl, he is furious against this one. A third miss has come to capture his affection; and when he has been left asleep, or resting in his cage, he has always the same word, but different in the inflection wheedling, angry, or nearly indifferent, as either of the three persons comes near him. Jaco's pronunciation is scanned in many meters. Only one young student has had the privilege of retaining his affection unmarred.

Jaco had been left in the country for a whole week in the winter. Alone and isolated, he was taken care of by a person who was not constantly with him. The young student, accompanied by a tutor, came to pass a few days in the house. At the sight of the youth, Jaco, surprised, called out, "Momon! Momon!" "It was affecting," they wrote me, "to see so great signs of joy." I have also myself witnessed similar signs of joy at the coming of the student. Jaco's speech at such times is always in harmony with his feelings. In the pleasant season Jaco's cage is put outdoors; and at meal times, knowing very well what is going on within, he keeps up a steady course of suppliant appeals for attention. His appeals cease at once if I go out with fruit in my hand, and if I go toward him he utters a prattle of joy that sounds like musical laughter. These manifestations indicate that he is happy at seeing that he has been thought of.

I close these anecdotes, as I began them, by repeating that animals communicate their impressions, and the feelings that move them, by various modulations of their inarticulate cries, which are incomprehensible to us unless we have succeeded by attentive observation in connecting them with the acts that follow or precede them. We have also seen that the articulation of a few words learned by parrots aids us greatly in learning the meaning of these different inflections.

The extension of these studies would furnish much of interest; but further observations should be made upon the same animals for a longtime continuously, relating especially to their peculiar instincts as manifested by their various cries. We might then, by comparing and relating acts and cries, reach the point of comprehending and perhaps fixing the meaning in many cases where we are now in ignorance. Every one has noticed a few facts, and has interpreted and related them, but much is still wanting for the co-ordination of them in the point of view of the signification of the language and communication of animals among themselves. It has not been made in a general sense. —Translated for the Popular Science Monthly from the Revue Scientifique.

* * * * *



MODIFICATION OF OUR CLIMATE.

By JOSEPH WALLACE.

Every now and then some weather sage predicts extremely cold winters, and another ventures to say that the sun is gradually losing heat and in time Arctic cold will prevail over the globe. Whatever may have been the changes during the vast cycles of time prior to the advent of man, or whatever may be the changes in the time to come, one thing is quite certain; that our climate has been much modified within the past two or three thousand years.

"There have been fifteen climatic changes since the beginning of the glacial age, each change lasting 10,500 years, and each change reversing the season in the two hemispheres, the pole which had enjoyed continuous summer being doomed to undergo perpetual winter for 10,500 years, and then passing to its former state for an equal term. The physical changes upon the earth's surface during the past 80,000 years modified the changes of climate even in the Arctic regions, so that the intense cold of the former epochs was much modified during the latter epochs." Reckoning these climatic changes in their order, we had entered the epoch of a more genial temperature about fifteen hundred years ago; and if no disturbing change takes place during the present epoch, we may reasonably expect a gradual modification of our winters for nine thousand years to come. The changes to intense cold from perpetual summer during the greater part of the glacial period are supposed to have been caused by the high temperature of the north pole as compared to that of the south pole, owing to the distribution of land around the two, the south having almost none. Dr. Croll thinks it was caused by the varying inclination of the earth's axis, which produced the relative position of the two poles toward the sun to be periodically reversed at distant periods. Dr. James Geikie agrees with Croll on the reverse of seasons every 10,500 years during certain periods of high ellipticity of the earth's orbit.

But it may be asked, "How could the fauna and flora propagate themselves under such conditions?" The flora itself at the quaternary age was of extreme vigor. We know this from the little which is left us, but more especially from the presence of a large number of herbivorous animals—stags, horses, elephants, rhinoceros, etc.—which animated the plains and valleys of Europe and America at the same time. Evidently they could not have lived and propagated themselves without abundant vegetation for nourishment and development.

That which has deceived the adherents of the glacial theory, as understood in its absolute sense, is, they have generally placed a too high estimate on its extent and intensity. It needs but a little effort of the reasoning powers to come to the conclusion that the earth had cooled to the degree that all animal and vegetable life could exist upon it, and that a portion of the earth's surface permanently covered with snow and ice was absolutely indispensable to the existence, perpetuity, and well-being of animal and vegetable life. Again, they have attributed to the glaciers the rocks, gravels, and other material which they have found spread here and there long distances from the mountains. The transportation of the so-called erratic rocks has appeared inexplicable in any other way, and the piles of rock and gravel have been considered so many moraines, that is, deposits of diverse material transported by the glaciers. They do not regard the probability of other agents taking the place of glaciers, and undervalue the moving power of water. Water in liquid state has often produced analogous effects, and it has often been the error of the glacialists to confound the one with the other. The erratic rocks and the moraines are undoubtedly the ordinary indications of the ancient gravels, but, taken isolatedly, they are not sufficient proof. In order to convince they should be accompanied with a third indication, which is the presence of striated rocks which we find in the neighborhood of our actual glaciers. When all these signs are together then there is hardly a possibility of error, but one alone is not sufficient, because it can be the effect of another cause.

No doubt the temperature was really lower at the quaternary age and at the epoch generally assigned to man's advent in European countries, but the difference was not so great as some say. A lowering of four degrees is sufficient to explain the ancient extension of the glaciers. We can look on this figure as the maximum, for it is proved to-day that humanity played the main role in the glacial phenomena. The beds of rivers and the alluvia are there to tell that all the water was not in a solid state at that time, that the glaciers were much more extended than in our days, and that the courses of the rivers were infinitely more abundant. When this is understood we can reasonably reduce the extension of the ancient glaciers, the lowering of the temperature at the quaternary age, and account for the uninterrupted life of the fauna and flora. However, we must not fall into the opposite excess and assert, as some have done, that the glacial period is comparatively recent, the traces of which are too plain and fresh in some localities to assign to it an age prior to man, and that the temperature has rather lowered itself since this epoch. The ancient extension of the glaciers has been followed by a corresponding growth and extension of animal life, thus proving that the permanence of glaciers is a wise provision and absolutely essential to man and the high orders of animals and vegetation. The ancient extension does not prove alone that it was much colder than in historic times, for the animals themselves are proof of this. At that time the plains of Europe, and of France in particular, were animated by herds of reindeer, gluttons, camels, and marmots, which one does not find to-day except in the higher latitudes or more considerable heights. The mammoth and rhinoceros are no exception to this, for naturalists know they were organized to live in cold countries.

Space will not permit us to pursue this point further, or speculate on the probable climatic conditions of the ice age; but we can carry ourselves back a few thousand years and describe the climate of Europe and neighboring countries of Africa and Asia. Herodotus describes the climate of Scythia in terms which would indicate in our day the countries of Lapland and Greenland. He shows us the country completely frozen during eight months of the year; the Black Sea frozen up so that it bore the heaviest loads; the region of the Danube buried under snow for eight months, and watered in summer by the abundant rains which gave to the river its violent course. The historian adds that the ass cannot live in Scythia on account of the extreme cold which reigns there. The following century Aristotle makes the same remarks concerning Gaul. His contemporary, Theophrastes, tells us that the olive tree did not succeed in Greece more than five hundred furlongs from the sea. We can assure ourselves that both the ass and the olive thrive in these countries at the present day.

Three centuries later, Caesar speaks frequently and emphatically of the rigor of winters and early setting in of cold in France, the abundance of snow and rain, and the number of lakes and marshes which became every moment serious obstacles to the army. He says he is careful not to undertake any expedition except in summer. Cicero, Varro, Possidonius, and Strabo insist equally on the rigor of the climate of Gaul, which allows neither the culture of the vine nor the olive. Diodorus of Sicily confirms this information: "The cold of the winters in Gaul is such that almost all the rivers freeze up and form natural bridges, over which numerous armies pass quite safely with teams and baggages; in order to hinder the passengers to slip out upon the ice and to render the marching more secure, they spread straw thereon."

Virgil and Ovid insist on the severity of cold in the regions of the Danube. The first describes the inhabitants of these miserable countries withdrawing themselves into caves dressed with the skins of wild beasts. Ovid, who had passed several years of his life in that region, is more precise in his description. He says the wine has changed itself here (Black Sea) into a solid frozen mass; one gives it to drink by pieces. Fearing of being accused of poetic exaggeration he appeals to the testimony of two ancient governors of Moesia, who could establish the facts like himself. The author who would give such accounts of the Black Sea in our days would risk his reputation for veracity.

Italy, too, experienced its part of the cold in early days. Virgil tells us of the snows being, heaped up, rivers which carried ice along, the sad winter which split the stone and bound up the course of large streams, and all this in the warmest part of Italy, at the base of the walls of Taranto. Heratius affirms that the Soracte, a neighboring mountain of Rome, was whitened with thick snow, rivers frozen, and the country covered with snow. To-day the snow stays very little upon the Soracte and never in the country around Rome. During the four or five centuries which followed, writers speak of the severity of climate in Northern Italy, the lagoons on the Adriatic being frozen over. Algiers was much colder then than now. The Danube, Rhine, and other rivers in Europe, the Nile in Africa, the Amazon in South America, the Mississippi and Missouri in North America, had quite different volumes two thousand years ago than their present actual ones, and they especially rolled much greater masses of water.

There is everything to show a modification of climate in our own days. If this goes on in the future as in the past, there will be a marked difference in the temperature two or three hundred years from now. Even a degree in a thousand years would effect a great change in the course of time. The lowering of four degrees established the ancient extension of glaciers, though it did not interrupt animal or vegetable life. Fifty-four of the fifty-seven species of Mollusca have outlived the glacial age, and all our savage animals—even a certain number which have disappeared—date equally from the quaternary, and were contemporary with the great extension of the glaciers.—Popular Science News.

* * * * *



THE ERUPTION OF KRAKATOA.

Before the year 1883 physical geographers, in speaking of the most disastrous volcanic eruption on record, referred first, in point of time, to the celebrated eruption of Vesuvius, in A.D. 79, when the cities of Herculaneum, Pompeii and several smaller towns on the slope of the mountain were destroyed by lava or buried under a mass of pumice stones and ashes; second to that of Hecla and Skaptar Jokull, contiguous mountains in Iceland, in 1783, when two enormous lava streams, one 15 miles wide and over 100 ft. deep and the other scarcely inferior, flowed, the first, 50 miles and the other 40, till they reached the sea, pouring a flood of white hot lava into the ocean, destroying everything in their paths and killing in the waters of the ocean the fish, the mainstay of the inhabitants, who were reduced by the disaster, directly or indirectly, to less than five-sixths of their former strength; and third to that of Galungung, in 1822, which devastated such an immense area in Java; but all the eruptions known besides were as mere child's play to the terrible one of Krakatoa in 1883.

If the reader will examine the map of the East Indies he will find represented in the straits of Sunda, which lie between Sumatra and Java, the little island of Krakatoa. In maps made before 1883 he will hunt in vain for the name, for like Bull Run before 1861, it was then unknown to fame, though navigators who passed through the straits knew it as a beautiful tropical isle, with an extinct volcanic cone in the center. In the beginning of 1883, however, the little well behaved island showed symptoms of wrath that boded no good to the larger islands in the vicinity. Noted for the fine fruits with which it abounded, it was a famous picnic ground for towns and cities even 100 miles away, and when the subterranean rumblings and mutterings of wrath became conspicuous the people of the capital of Java, Batavia, put a steamboat into requisition and visited the island in large numbers. For a time the island was constantly in a slight tremor, and the subterranean roar was like the continued but distant mutterings of thunder, but the crisis was reached August 23, at 10 o'clock A.M. It was a beautiful Sunday morning and the waters of the straits of Sunda were like that sea of glass, as clear as crystal, of which John in his apocalyptic vision speaks. The beauty that morning was enhanced by the extraordinary transparency of the tropical air, for distant mountain ranges seemed so near that it seemed possible to strike them with a stone cast from the hand. Only the mysterious rumblings and mutterings of the pent up forces beneath the island disturbed the breathless calm and silence that lay on nature—the calm before the terrible storm—the mightiest, the most awful on record! It burst forth! Sudden night snatched away day from the eyes of the terrified beholders on the mainland, but the vivid play of lightnings around the ascending column of dust penetrated even the deep obscurity to a distance of 80 miles. This awful darkness stretched within a circle whose diameter was 400 miles, while more or less darkness reigned within a circle with a diameter three times as great. Within this latter area dust fell like snow from the sky, breaking off limbs of trees by its weight miles distant, while in Batavia, 100 miles away from the scene of the disaster, it fell to the depth of several inches. The explosions were so loud as to be distinctly heard in Hindostan, 1,800 miles away, and at Batavia the sound was like the constant roar of cannon in a field of battle. Finally the whole island was blown to pieces, and now came the most awful contest of nature—a battle of death between Neptune and Vulcan; the sea poured down into the chasm millions of tons, only to be at first converted into vapor by the millions of tons of seething white hot lava beneath. Over the shores 30 miles away, waves over 100 ft. high rolled with such a fury that everything, even to a part of the bedrock, was swept away. Blocks of stone, of 50 tons weight were carried two miles inland. On the Sumatra side of the straits a large vessel was carried three miles inland. The wave, of course growing less in intensity, traveled across the whole Indian Ocean, 5,000 miles, to the Cape of Good Hope and around it into the Atlantic. The waves in the atmosphere traveled around the globe three times at the rate of 700 miles per hour. The dust from the volcano was carried up into the atmosphere fully twenty miles and the finest of it was distributed through the whole body of air. The reader doubtless remembers the beautiful reddish or purple glow at sunrise and sunset for fully six months after August, 1883—that glow was caused by volcanic dust in the atmosphere interfering with the passage of the sun's rays of the upper part of the solar spectrum, more manifest at sun rising and setting than at other times during the day, because at these periods the sun's rays have to travel obliquely through the atmosphere, and consequently penetrating a very deep layer, were deprived of all their colors except the red.

The loss of life was appalling. The last sight on earth to 35,000 people was that of the awful eruption. Engulfed in the ocean or covered with heaps of ashes, a few hours after the eruption commenced the awful work was done, and that vast multitude had vanished from off the face of the earth. The fact that in the neighborhood of the mountain there was a sparse population accounts for there not being even a far greater loss of life.

Notwithstanding the awfulness of volcanic and earthquake phenomena, there is some silver lining to the dark clouds. They prove that the earth is yet a living planet. Centuries must pass away before it will become like the moon—a dead planet—without water, air or life. Our satellite is a prophecy indeed of what the earth must eventually become when all its life forces, its internal energies, are dissipated into space.—Granville F. Foster, Min. Sci. Press.

* * * * *



PENTAPTERYGIUM SERPENS.

This is one of five species of Himalayan plants which, until recently, were included in the genus vaccinium. The new name for them is ugly enough to make one wish that they were vacciniums still. Pentapterygium serpens is the most beautiful of the lot, and, so far as I know, this and P. rugosum are the only species in cultivation in England. The former was collected in the Himalayas about ten years ago by Captain Elwes, who forwarded it to Kew, where it grows and flowers freely under the same treatment as suits Cape heaths. Sir Joseph Hooker says it is abundant on the Sikkim mountains at from 3,000 to 8,000 feet elevation, and that it usually grows on the stout limbs of lofty trees. In this it resembles many of the rhododendrons of that region, and it has been suggested that they are epiphytic from force of circumstances, not from choice. On the ground they would have no chance against the other vegetation, which would strangle or starve them out. Remove them from this struggle for existence, and they at once show their preference for rich soil and plenty of it. All the pentapterygiums have the lower part of the stem often swelling out into a prostrate trunk, as thick as a man's leg sometimes, and sending out stout branching roots which cling tightly round the limbs of the tree upon which it grows. These swollen stems are quite succulent, and they serve as reservoirs of moisture and nourishment. In the wet season they push out new shoots, from which grow rapidly wands three or four feet long, clothed with box-like leaves, and afterward with numerous pendulous flowers. These are elegant in shape and richly colored. They are urn-shaped, with five ribs running the whole length of the corolla, and their color is bright crimson with deeper colored V-shaped veins, as shown in the illustration of the flowers of almost natural size. They remain fresh upon the plant for several weeks. The beautiful appearance of a well grown specimen when in flower may be seen from the accompanying sketch of the specimen at Kew, which was at its best in July, and remained in bloom until the middle of September.



P. rugosum is also grown as a greenhouse plant at Kew, where it has been in cultivation about twenty years. It has larger leaves and a more bushy habit than P. serpens, while the flowers are produced in fascicles on the old wood. They are as large as those here figured, but differ in color, being whitish, with brown-red V-shaped marks. Both species may be propagated from cuttings. The plants thrive in sandy peat, and they like plenty of moisture at all times.—W. Watson, in The Gardeners' Magazine.



* * * * *



THE PERFORATION OF FLOWERS.

The subject of the relations and adaptations which exist between flowers and insects does not appear to excite as much popular attention as many other branches of natural science which are no more interesting. Sprengel, Darwin, and Hermann Muller have been the chief authors in giving us our present knowledge and interest in the study; Sir John Lubbock has helped to popularize it, and Prof. W. Trelease and others have carried on the work in this country.

The perforation as well as the fertilization of flowers has received attention, but there is a wide field for further study for those who have leisure to pursue it, as it requires much time and patience, as well as closeness and accuracy of observation.

The accompanying figures, from drawings by Mr. C.E. Faxon, show a few characteristic perforations and mutilations, and also represent two of the principal kinds of insects which make them.

Any one interested in the subject will find an excellent brief review of the work already done, a fair bibliography, and a list of perforated flowers in Professor L.H. Pammel's paper on the "Perforation of Flowers," in the Transactions of the St. Louis Academy of Science, vol. v., pp. 246-277.

The general beauty of flowers is usually not greatly marred by the perforations except in a few cases, as when the spurs of columbines and corollas of trumpet creepers are much torn, which frequently happens.

The great object of the perforations by insects is the obtaining of the concealed nectar in an easy way. Very naturally, flowers which depend on insect agency for fertilization rarely produce seed when punctured if they are not also entered in the normal way. Perforating is only practiced by a small number of species of insects, and many but not all of the perforators do so because their tongues are too short to reach the nectar by entering the flower. Some obtain nectar from the same kind of flower both in the normal way and by perforating.

The chief perforators of flowers, in this part of the continent at least, appear to be some kinds of humble bees (Bombus) and carpenter bees (Xylocopa). These insects have developed an unerring instinct as to the proper point to perforate the corollas from the outside, in order to readily get at the nectar. The holes made by the humble bees and by the carpenter bees are usually quite different and easily distinguished.

The humble bees have short, stout, blunt jaws, ill adapted for cutting, and the perforations made by them are apparently always irregular in shape, and have jagged edges. It has been stated that the humble bees often bore through the tubes of their corollas with their maxillae, but in all cases observed by me the mandibles were first brought into use in effecting an opening. The noise caused by the tearing is often audible for a distance of several feet.

The true jaws of the carpenter bees are not any more prominent or better adapted for making clean-cut perforations than those of the humble bees; but behind the jaws there is a pair of long, sharp-pointed, knife-like, jointed organs (maxillae) which seem to be exclusively used on all ordinary occasions in making perforations. The inner edges of these maxillae are nearly straight, and when brought together they form a sharp-pointed, wedge-shaped, plow-like instrument which makes a clean, narrow, longitudinal slit when it is inserted in the flower and shoved forward. The slits made by it are often not readily seen, because the elasticity of the tissues of some flowers causes them to partially close again. When not in use the instrument can be folded back, so that it is not conspicuous. The ordinary observer usually sees no difference between the humble bees and the carpenter bees, but they may be readily distinguished by a little close observation.



No doubt, in some of the recorded cases of perforations, carpenter bees have been mistaken for humble bees. The heads of all our Northern humble bees are rather narrow, retreating from the antennae toward the sides, and with a more or less dense tuft of hair between the antennae. The abdomen, as well as the thorax, is always quite densely covered with hair, which may be black or yellowish or in bands of either color. With possibly one or two exceptions, the only species I have seen doing the puncturing is Bombus affinis, Cresson.

The carpenter bees (Xylocopa Virginica) of this region have the head very broad and square in front, and with no noticeable hair between the antennae. The heads of the male and female differ strikingly. In the male the eyes are lighter colored and are hardly half as far apart as in the female, and the lower part of the face is yellowish white. The female has eyes smaller, darker, and very far apart, and the whole face is perfectly black. The abdomen is broad, of a shining blue-black color, very sparsely covered with black hairs, except on the first large segment nearest the thorax. On this segment they are more dense and of the same tawny color as those on the thorax. But it is particularly from the character of the head that the amateur observer of the perforators may soon learn to distinguish between a Xylocopa and a Bombus as they work among the flowers. It is also interesting to know that the Xylocopas are not so inclined to sting as the humble bees, and the males, of course, being without stinging organs, may be handled with impunity.

Among other insects, honey bees have been said to perforate flowers, but authentic instances are rare of their doing much damage, or even making holes. I have only recorded a single instance, and in this a honey bee was seen to perforate the fragile spurs of Impatiens. When searching for nectar they quite commonly use the perforations of other insects. Wasps and other allied insects also perforate for nectar. My only observations being a Vespa puncturing Cassandra calyculata, an Andrena (?) perforating the spurs of Aguilegia, and Adynerus foraminatus biting holes close to the base on the upper side of rhododendron flowers. The holes made by some of the wasp-like insects are often more or less circular and with clean-cut edges. The ravages committed by larvae, beetles and other insects in devouring flowers, or parts of them, do not properly come under the head of perforations.

The question as to the cause of the handsome corollas of the trumpet creeper (Tecoma radicans) being so often split and torn has been accounted for in various ways in published notes on the subject. Humming birds and ants have been blamed, the humming birds being such constant visitors of these flowers that it really seemed as though they must be the authors of the mischief. I have often watched them when they appeared as though they were pecking at the blossoms, but careful examinations, both before and after their visits, always failed to show any trace of injury. Finally, on July 26, 1890, I was rewarded by seeing a number of Baltimore orioles vigorously pecking at and tearing open a lot of fresh blossoms, and this observation was afterward repeated. That the oriole should do this was not surprising, considering its known habits in relation to some other flowers. J.G. JACK.

[Mr. Jack adds a list of sixteen plants whose flowers he has seen punctured by the carpenter bee and seventeen others whose flowers were punctured by the humble bee. He names more than thirty other flowers which he has found perforated without having seen or identified the authors of the mischief.—ED.]—Garden and Forest.

* * * * *



ELECTRICITY IN HORTICULTURE.

The influence of electricity upon vegetation has been the subject of numerous investigations. Some have been made to ascertain the effects of the electric current through the soil; others to ascertain the effect of the electric light upon growth through the air. Among the latter are those of Prof. L.H. Bailey of the Cornell University Agricultural Experiment Station. In Bulletin No. 30 of the Horticultural Department is given an account of experiments with the electric light upon the growth of certain vegetables, like endive, spinach, and radish; and upon certain flowers like the heliotrope, petunia, verbena primula, etc. The results are interesting and somewhat variable. The forcing house where the experiments were carried on was 20 x 60 ft., and was divided into two portions by a partition. In one of these the plants received light from the sun by day and were in darkness at night. In the other they received the sunlight and in addition had the benefit of an arc light the whole or a part of the night. The experiment lasted from January until April during two years, six weeks of the time the first year with a naked light and the balance of the time with the light protected by an ordinary white globe. It is not the purpose here to enter into any great details, but to give the general conclusions.

The effect of the naked light running all night was to hasten maturity, the nearer the plants being to the light the greater being the acceleration. The lettuce, spinach, etc., "ran to seed" in the "light" house long before similar plants in the dark. An examination of the spinach leaves with the microscope showed the same amount of starch in each, but in the electric light plants the grains were larger, had more distinct markings and gave a deeper color with iodine.

With lettuce it was found that the nearer the plants were to the light the worse the effect; and conversely those furthest away were the best developed. Cress and endive gave the same results. In the case of the latter, some of the plants were shaded from the light by an iron post, and these grew better and were larger than those exposed to its direct rays. The average weight of eight plants in full light was 49.6 grains, as opposed to an average of six plants in the shade of 93.8 grains. Radishes were strongly attracted to the light and moved toward it during the night. During the day they straightened up, but moved again toward the light at night. The plants nearest the lamp made a poor growth and were nearly dead at the end of six weeks. Averaging the weight of plant, of top and of tuber, it was found that those grown in the dark were heavier in every instance than those grown in the light; and the percentage of marketable tubers from the light-grown plants was twenty-seven, as opposed to seventy-eight in the dark. Chemical analyses showed the plants in the light to be more mature than those in the dark, although they were much smaller. Dwarf peas showed the same facts, those in full light being smaller than those in the dark. The former bloomed a week earlier than the latter, but the production of seed was less, being only about four-sevenths as great.

Further experiments were made by excluding the sun during the day and exposing the plants to the diffused electric light only. In all cases, with radishes, lettuce, peas, corn, and potatoes, the plants died in about four weeks. Only a little starch and no chlorophyl was found in the plants deprived of sunlight and only receiving the electric light. Thus the experiments with a naked light showed conclusively that "within range of an ordinary forcing house the naked arc light running continuously through the night is injurious to some plants." In no case did it prove profitable.

Experiments with the light inclosed in a white globe and running all night were different in their results. The effect was much less marked. Lettuce was decidedly better in the light house; radishes were thrifty but did not produce as much as in the dark house. A third series of experiments with the naked light running a part of the night only were also made. Radishes, peas, lettuce, and many flowers were experimented upon. The lettuce was greatly benefited by the light. "Three weeks after transplanting (Feb. 5)," we are told, "both varieties in the lighthouse were fully 50 per cent. in advance of those in the dark house in size, and the color and other characters of the plants were fully as good. The plants had received at this time 701/2 hours of electric light. Just a month later the first heads were sold from the light house, but it was six weeks later when the first heads were sold from the dark house. In other words, the electric light plants were two weeks ahead of the others. This gain had been purchased by 1613/4 hours of electric light, worth at current prices of street lighting about $7."

This experiment was repeated with the same results. In the second experiment the plants receiving eighty-four hours of electric light, costing $3.50, were ready for market ten days before the plants in the dark house. The influence of the light upon color of flowers was variable. With tulips the colors of the lighted plants were deeper and richer than the others, but they faded after four or five days. Verbenas were injured in every case, being of shorter growth and losing their flowers sooner than those in the dark house. "Scarlet, dark red, blue and pink flowers within three feet of the light soon turned to a grayish white." Chinese primulas seven feet from the light were unaffected, but those four feet away were changed. Lilac colors were bleached to pure white when the light struck them fairly. An elaborate series of tables of the effect of the light is given in the paper. The author believes it possible that the electric light may be used some day to pecuniary advantage in floricultural establishments.

These experiments naturally open up many questions. Those which will be of most importance to the practical man will be such as relate to the benefits to be derived from the use of the electric light. That electricity has a great effect upon vegetation can no longer be denied. What remains now is to ascertain how to use the force with the most economy and to the best advantage. If by its use early vegetables will be made earlier, bright flowers be made brighter, it will be a question of only a short time before it will come into general use. To the student of plant physiology there are also many questions of interest, but into these it is not the intention to enter. Prof. Bailey's general conclusions are, in part, as follows: "There are a few points which are clear: the electric light promotes assimilation, it often hastens growth and maturity, it is capable of producing natural flavors and colors in fruits, it often intensifies colors of flowers and sometimes increases the production of flowers. The experiments show that periods of darkness are not necessary to the growth and development of plants. There is every reason, therefore, to suppose that the electric light can be profitably used in the growing of plants. It is only necessary to overcome the difficulties, the chief of which are the injurious influences upon plants near the light, the too rapid hastening to maturity in some species, and in short the whole series of practical adjustments of conditions to individual circumstances. Thus far, to be sure, we have learned more of the injurious effects than of the beneficial ones, but this only means that we are acquiring definite facts concerning the whole influence of electric light upon vegetation; and in some cases, notably in our lettuce tests, the light has already been found to be a useful adjunct to forcing establishments.... It is highly probable that there are certain times in the life of the plant when the electric light will prove to be particularly helpful. Many experiments show that injury follows its use at that critical time when the planetlet is losing its support from the seed and is beginning to shift for itself, and other experiments show that good results follow from its later use.... On the whole, I am inclined toward Siemens' view that there is a future for electro-horticulture."

JOSEPH P. JAMES. Washington, Jan. 20, 1892.

* * * * *



ELECTRICITY IN AGRICULTURE. By CLARENCE D. WARNER.

It is well known that currents of electricity exist in the atmosphere. Clouds are charged and discharged. There is a constant change of electricity from earth to air and from air to earth, the latter being the great reservoir for all electricity. Hills, mountain peaks, trees, high chimneys, spires, in fact all points elevated above the earth's surface assist greatly in charging and discharging the atmosphere. Again, if two iron rods are driven into the earth and connected by a copper wire with an electrometer in the circuit, the instrument is almost immediately affected, showing that currents of electricity are running through the ground. Now, what is the function of these atmospheric and ground electric currents? Many scientists are agreed that certain forms of precipitation are due to electrical action; but my observations have led me to believe conclusively that electricity is a potent factor in the economy of nature, and has more to do with the growth and development of plants than has hitherto been known. Davy succeeded in the decomposition of the alkalies, potash and soda, by means of electric currents. In our laboratories, water and ternary compounds are rapidly decomposed by the battery, and we may reasonably suppose that that which is effected in our laboratories by artificial means takes place in the great laboratory of nature on a grander and more extended scale.

Plant food is carried throughout the plant by means of the flow of sap; these currents circulate through all the rootlets and center, as it were, in the stalk, carrying their tiny burdens of various elements and depositing them in their proper places. That this phenomenon of circulation is due to electricity cannot be doubted. Most plants grow more rapidly during the night than in the day. May not the following be a reason for this?

We have already mentioned how electric currents pass from air to earth and vice versa; at night the plant is generally covered with dew and the plant itself becomes a good conductor, and, consequently, currents of electricity pass to each through this medium, and during the passage convert soil elements into plant food and stimulate the upward currents to gather up the dissolved elements and carry them to their proper places.

From the time electricity became a science, much research has been made to determine its effect, if any, upon plant growth. The earlier investigations gave in many cases contradictory results. Whether this was due to a lack of knowledge of the science on the part of the one performing the experiments, or some defect in the technical applications, we are not prepared to say; but this we do know, that such men as Jolabert, Nollet, Mainbray and other eminent physicists affirmed that electricity favored the germination of seeds and accelerated the growth of plants; while, on the other hand, Ingenhouse, Sylvestre and other savants denied the existence of this electric influence. The heated controversies and animated discussions attending the opposing theories stimulated more careful and thorough investigations, which establish beyond a doubt that electricity has a beneficial effect on vegetation. Sir Humphry Davy, Humboldt, Wollaston and Becquerel occupied themselves with the theoretical side of the question; but it was not till after 1845 that practical electroculture was undertaken. Williamson suggested the use of gigantic electrostatic machines, but the attempts were fruitless. The methods most generally adopted in experiments consisted of two metallic plates—one of copper and one of zinc—placed in the soil and connected by a wire. Sheppard employed the method in England in 1846 and Forster used the same in Scotland. In the year 1847 Hubeck in Germany surrounded a field with a network of wires. Sheppard's experiments showed that electricity increased the return from root crops, while grass perished near the electrodes, and plants developed without the use of electricity were inferior to those grown under its influence. Hubeck came to the conclusion that seeds germinated more rapidly and buckwheat gave larger returns; in all other cases the electric current produced no result. Professor Fife in England and Otto von Ende in Germany carried on experiments at the same time, but with negative results, and these scientists advised the complete abandonment of applying electricity to agriculture. After some years had elapsed Fichtner began a series of experiments in the same direction. He employed a battery, the two wires of which were placed in the soil parallel to each other. Between the wires were planted peas, grass and barley, and in every case the crop showed an increase of from thirteen to twenty-seven per cent. when compared with ordinary methods of cultivation.

Fischer, of Waldheim, believing atmospheric electricity to aid much in the growth and development of plants, made the following tests:

He placed metallic supports to the number of about sixty around each hectare (2.47 acres) of loam; these supports were provided at their summits with electrical accumulators in the form of crowns surmounted with teeth. These collectors were united by metallic connection. The result of this culture applied to cereals was to increase the crop by half.

The following experiment was also tried: Metallic plates sixty-five centimeters by forty centimeters were placed in the soil. These plates were alternately of zinc and copper and placed about thirty meters apart, connected two and two, by a wire. The result was to increase from twofold to fourfold the production of certain garden plants. Mr. Fischer says that it is evidently proved that electricity aids in the more complete breaking up of the soil constituents. Finally he says that plants thus treated mature more quickly, are almost always perfectly healthy, and are not affected with fungoid growth.

Later, N. Specnew, inspired by the results arrived at by his predecessors, was led to investigate the influence of electricity on plants in every stage of their development; the results of his experiments were most satisfactory and of practical interest. He began by submitting different seeds to the action of an electric current, and found that their development was rendered more rapid and complete. He experimented with the seeds of haricot beans, sunflowers, winter and spring rye. Two lots, of twelve groups of one hundred and twenty seeds each, were plunged into water until they swelled, and while wet the seeds were introduced into long glass cylinders, open at both ends. Copper disks were pressed against the seeds, the disks were connected with the poles of an induction coil, the current was kept on for one or two minutes and immediately afterward the seeds were sown. The temperature was kept from 45 deg. to 50 deg. Fahrenheit, and the experiments repeated four times. The following table shows the results:

Peas. Beans. Barley. Sunflowers. Days. Days. Days. Days. Electrified seeds developed in 2.5 3 2 8.5 Non-electrified seeds developed in 4 6 5 15

It was also observed that the plants coming from electrified seeds were better developed, their leaves were much larger and their color brighter than in those plants growing from non-electrified seeds. The current did not affect the yield.

At the Botanical Gardens at Kew, the following experiment was tried:

Large plates of zinc and copper (0.445 meter and 0.712 meter) were placed in the soil and connected by wires, so arranged that the current passed through the ground; the arrangement was really a battery of (zinc earth copper). This method was applied to pot herbs and flowering plants and also to the growing of garden produce; in the latter case the result was a large crop and the vegetables grown were of enormous size.

Extensive experiments in electroculture were also made at Pskov, Russia. Plots of earth were sown to rye, corn, oats, barley, peas, clover and flax; around these respective plots were placed insulating rods, on the top of which were crown-shaped collectors—the latter connected by means of wires. Atmospheric electricity was thus collected above the seeds, and the latter matured in a highly electrified atmosphere; the plots were submitted to identical conditions and the experiments were carried on for five years. The results showed a considerable increase in the yield of seed and straw, the ripening was more rapid and the barley ripened nearly two weeks earlier with electroculture. Potatoes grown by the latter method were seldom diseased, only to 5 per cent., against 10 to 40 per cent. by ordinary culture.