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THE NATURALIST IN NICARAGUA
BY
THOMAS BELT
WITH AN INTRODUCTION BY ANTHONY BELT, F.L.S.
HOC SOLUM SCIO QUOD NIHIL SCIO.
THE NATURALIST IN NICARAGUA
BY
THOMAS BELT.
EVERYMAN, I WILL GO WITH THEE, & BE THY GUIDE IN THY MOST NEED TO GO BY THY SIDE.
LONDON: PUBLISHED BY J.M. DENT & SONS LTD. AND IN NEW YORK BY E.P. DUTTON & CO.
INTRODUCTION.
In the "Life and Letters of Charles Darwin," edited by his son, Mr. Francis Darwin (volume 3 page 188), the following passage occurs:—
"In the spring of this year (1874) he read a book which gave him great pleasure, and of which he often spoke with admiration, "The Naturalist in Nicaragua," by the late Thomas Belt. Mr. Belt, whose untimely death may well be deplored by naturalists, was by profession an engineer, so that all his admirable observations in natural history, in Nicaragua and elsewhere, were the fruit of his leisure. The book is direct and vivid in style, and is full of description and suggestive discussions. With reference to it my father wrote to Sir J.D. Hooker: 'Belt I have read, and I am delighted that you like it so much; it appears to me the best of all natural history journals which have ever been published.'"
Now that the book so highly recommended by such an authority is about to be introduced to a public which has hitherto only known it by hearsay, it will be interesting to inquire into the reason of its appreciation by such men as Darwin and Hooker—and Lyell, Huxley, and Wallace, with other leaders of the scientific world of that day, might be quoted to the same effect—and to give some particulars of the author's short active life.
The Belts were an old family which had been established at Bossal in Yorkshire since the reign of Richard II. The main line died out some twenty years ago, but about the beginning of the eighteenth century a member of the family went to the Tyne to join the well-known ironworks of Crawley at Winlaton. He and his descendants remained with the firm for over a century, and he was the great-great-grandfather of the grandfather of Thomas Belt born at Newcastle-on-Tyne on November 27, 1832.
Thomas was the fourth child of a family of seven. His mother possessed a singularly sweet and beautiful disposition; his father, much given to hobbies, was stern and unbending, and he himself combined an almost womanly gentleness with a quiet determination that unflinchingly faced all obstacles. With a high sense of personal honour, unassuming and even-tempered, he was only roused to anger by acts of oppression or wanton cruelty. Then his indignation, though not loud, was very real, and he acted with a promptitude which would hardly have been expected from his usually placid demeanour. A story is told of how one day sitting at table he saw through the window a man belabouring a woman. Without saying a word, he rushed out, pinioned the offender by the elbows and, running him to the top of a steep slope in the street, gave him a kick which sent him flying down the declivity. The incident is recalled merely as an illustration of his practical way of dealing with difficulties which stood him in good stead in many an out-of-the-way corner of the world when contending with obstacles caused either by the perversity of man or the forces of nature. He never carried fire-arms even when travelling in the most unsettled districts, and his firm but conciliatory manner overcame opposition in a wonderful way. In ordinary life he was the kindest and most considerate of men, and his transparent sincerity made friends for him everywhere. Nor was he ever happier than when assisting others in those pursuits which occupied his own leisure.
The interesting question as to what led Belt to become a naturalist is difficult to answer. "Environment" nowadays accounts for much, but none of his brothers—and all the family had a similar bringing-up—showed any inclination for what with him became the ruling passion of his life. And yet, in a wider sense, "environment" had probably something to do with it. In the first half of the nineteenth century Newcastle could boast of a succession of field-naturalists unequalled in the country—Joshua Alder and Albany Hancock, who wrote the monograph on British nudibranchiate mollusca for the Ray Society; William Hutton and John Thornhill, botanists; W.C. Hewitson, Dr. D. Embleton, and John Hancock, zoologists; Thomas Athey and Richard Howse, palaeontologists—these, and others like them, were enthusiastically at work collecting, observing, recording, classifying. Fresh discoveries were being made every day; what are now commonplace scientific truisms wore then all the charm of novelty; the secrets of nature were being unveiled, and modern science was entering upon an ever-extending kingdom.
Into all this scientific activity Belt was born, and from his earliest years it may be said of him, as in the well-known lines it was said of Agassiz:—
"And he wandered away and away With Nature, the dear old nurse, Who sang to him night and day The rhymes of the universe."
"And whenever the way seemed long, Or his heart began to fail, She would sing a more wonderful song, Or tell a more marvellous tale."
"If happiness," he wrote in his twenty-second year, "consists in the number of pleasing emotions that occupy our mind—how true is it that the contemplation of nature, which always gives rise to these emotions, is one of the great sources of happiness."
The earliest instance which has been remembered of his fondness for animal life occurred when he was about three years old. He had been in the garden and came running to show his mother what he had found. Opening his carefully gathered up pinafore, out jumped two frogs—to the great dismay of the good lady, for frogs are first cousins to toads, the dire effects of whose glance and venom were known to every one.
He received the best education the town could give, and was fortunate in his schoolmasters—first Dr. J.C. Bruce of antiquarian fame, and then Mr. John Storey, second to none in his day as a north-country botanist.
Belt's father was much interested in horticulture; and, possessing some meteorological instruments, entrusted him, when only twelve years old, with the keeping of a set of observations which showed not only the barometric and thermometric readings twice a day, and the highest and lowest temperatures, but also the rainfall, the state of the sky, the form of the clouds, and the force and direction of the wind. The elaborately arranged columns, full of symbols and figures, look very quaint in the careful boyish handwriting, and must have absorbed much of his spare time.
Insects, however, had the greatest attraction for him. He writes in his journal: "I have made a great improvement in the study of entomology, to which I have an ardent attachment." And a little later: "I find I have not time to study so many things. I am afraid that I will not be able to carry on entomology and botany together; but entomology I will not give up." He had been studying "electricity, astronomy, botany, conchology, and geology." At the age of sixteen he wrote: "I feel a longing, a natural desire, to explore and understand the ways of science. I am ambitious of doing something that will deserve the praise or excite the admiration of mankind." When the praise and admiration came, no one could have been more indifferent to them than himself. Nature, his "nurse," had become his queen; and never was there a more devoted, whole-hearted subject, a more simple-minded follower of science for its own sake without any thought of the honour or glory that might accrue thereby.
On August 10, 1849, he records: "I have been thinking for the last few days about fixing on some subject or pursuit on which to devote my life, as it is of no use first starting one subject and then another, thus learning nothing. After giving it a good deal of consideration, I have determined on studying 'Natural History,' not confining myself to any one branch of that vast subject. As this is a subject on which I intend to devote my leisure hours during the greater part if not the whole of my lifetime, I consider it to be of the greatest importance that I should lay a good foundation for it. I therefore intend during the ensuing winter to study the English language and composition, so as to be able to describe objects and explain my sentiments with greater clearness and precision than I can at present." The last sentence illustrates the systematic thoroughness of all his work which was one reason of his success.
Belt's "leisure hours" were soon more numerous than he had anticipated when recording his determination to devote them to natural history. Already his health had shown signs of giving way, and presently there was a nervous break-down which necessitated his giving up all work and being out in the open air as much as possible. But what appeared to be probably the wrecking of his life provided the opportunity which might not otherwise have occurred of encouraging and developing his inborn love of nature. Becoming a member of the Tyneside Naturalists' Field Club, he interested himself greatly in the local fauna and flora, and formed very complete collections of the plants, insects, and shells. His name occurs frequently in the "Transactions" of the Club as the recorder of species new to the district. His health gradually improved, but it was doubtful whether he would be able to bear the strain of any indoor occupation, for which indeed he felt an ever-increasing aversion.
It was the time of the discovery of gold in Australia, and after much discussion he and his elder brother joined the stream of adventurers and sailed in 1852 for Victoria. In this rough "school of mines" he acquired that insight into the building-up of the earth's crust and that practical knowledge of minerals which served him so well in after-life as a mining engineer. But although the whole colony was in the grip of the gold-fever, Belt retained the same quiet habits of observation which had marked him at home—for there, as to whatever part of the world his work subsequently called him, the engineer was always at heart a naturalist. He proved an excellent observer, and a certain speculative tendency led him to group his observations so as to bring out their full theoretical bearing.
Amid real hard work he found time to evolve a theory of whirlwinds and to speculate upon the soaring of birds. A companion has recorded in the following terms another matter which engaged much of his attention at this time: "The boldest of his speculations, and one of the soundest, as after-events proved, was his plan for crossing the Australian continent. He proposed, at the time the government expedition was mooted, to replace the costly plans of the government by the following scheme:—That he and his brother Anthony (who was unfortunately lost in the "Royal Charter") should be conveyed to the Gulf of Carpentaria, with about twenty pack-horses loaded with provisions and water; that an escort should protect them for some twenty miles from the coast, and that then the two voyagers only, with their pack-horses, should make their way to Cooper's Creek, the farthest known accessible point from the Victorian settled districts. Belt argued justly: 'If we fail, only two lives will be lost, but all chances are in our favour; we are provided with water and food more than ample to cover the distance we have to travel. Every step of our road carries us homeward and to safety. If we never find a drop of water on the road, our animals have enough to carry those who have to bear the whole journey to their goal, and as the animals succumb they will be shot or turned adrift.' The event showed Belt's sagacity. The unfortunate government expedition left Melbourne loaded with camp-followers and impedimenta, and by the time they reached a few stages beyond Cooper's Creek were well-nigh exhausted. Burke, the leader of the expedition, in desperation started with his two men, Wills and King, and bravely struck out for the Gulf of Carpentaria. Through desert and fertile plains, not altogether destitute of water, they reached in safety the northern shore of Australia; but the energy, the courage, and the strength that took them this long, weary journey did not suffice to carry them back over double the distance to their camp. Brave hearts! they struggled on; but King only, and as a worn-out man, ever saw Cooper's Creek again. Belt's plan would have solved the problem without loss of life and at a tenth of the cost." He always regretted that he had not the means of carrying it out independently of government assistance.
After eight years in Australia Belt returned to England, married, and was successively manager of mining companies in Nova Scotia, North Wales, and Nicaragua, sandwiching in between these appointments a visit to Brazil to report upon some gold mines in the province of Maranham. In whatever part of the world his work took him he turned for rest and relaxation to the branches of natural science for which the locality offered the greatest opportunity.
In Nova Scotia he began those investigations into the cause and phenomena of the glacial period which were to be the study of the last years of his life, and to which he himself attached the greatest importance. In Wales he took up the question of the age of the rocks in the neighbourhood of Dolgelly, and after much study of their fossils proposed the now accepted classification of the Lingula flags of the Lower Silurian system into the Maenturog flags and slates, the Festiniog flags, and the Dolgelly slates. The collecting of lepidoptera was his chief amusement in Brazil, where he made his first acquaintance with the teeming life of the torrid zone and laid the foundation for those observations on tropical nature which his longer stay in Nicaragua gave rise to, and which are recorded in this book.
After his return from Central America, his services were in great request as a consulting mining engineer, and the succeeding years of his life were spent in almost continual travel: over all parts of Great Britain, to North and South Russia, Siberia, the Kirghiz Steppes, Mexico, and the United States. It was on one of his annual visits to Colorado that he was seized with sudden sickness and died on September 21, 1878, at the early age of forty-five.
Thomas Belt was an accurate and intelligent observer possessed of the valuable faculty of wonder at whatever is new or strange or beautiful in nature, and the equally valuable habit of seeking a reason for all he saw. Having found or imagined one, he went on to make fresh observations, and sought out new facts to see how they accorded with his supposed cause of the phenomena. "The Naturalist in Nicaragua" has therefore a value and a charm quite independent of the particular district it describes. As a mere book of travel it is surpassed by scores of other works. The country and the people of Nicaragua are too much like other parts of tropical Spanish America, with their dull, lazy inhabitants, to possess any novelty. There is little in the book that can be called adventure, and still less of geographical discovery.
And yet, the many and highly diversified phases in which life presents itself in the tropics enabled the skilled naturalist to fill a volume with a series of episodes, experiences, and speculations of which the reader will never tire. His keen powers of observation and active intellect were applied to various branches of scientific inquiry with unflagging ardour; and he had the faculty of putting the results of these inquiries in a clear, direct form, rendered the more attractive by its simplicity and absence of any effort at fine writing. He does not obtrude his own personality, and, like all genuine men, he forgets "self" over his subject. Instead of informing us whether or not he received "the salary of an ambassador and the treatment of a gentleman," he scatters before us, broadcast, facts interesting and novel, valuable hints for future research, and generalisations which amply repay a close study. Not alone the zoologist, the geologist, but the antiquarian, the ethnologist, the social philosopher, and the meteorologist will each find in these pages additions to his store of knowledge and abundant material for study.
With all this, the work is not a mere catalogue of dry facts: it is eminently a readable book, bringing vividly before us the various subjects with which it is concerned. Minutely accurate in his description of facts and bold in his reasoning upon them, Belt covered so much ground that some of his theories have not held their own; but others have stood the test of time and been absorbed into the world's stock of knowledge, while all bear witness to the singular grasp of his mind and have stimulated thought and observation—which is a great virtue in theories, be they true or false.
It has been already stated that Belt devoted the scanty leisure of his last years to the study of the glacial period, entering with zest into the consideration of its cause, the method of deposition of its beds, and the time-relationship of man to it—complex questions on which his imagination had full scope, and which, had his life been prolonged, his patient accumulation of evidence might have ultimately led him to suggest answers that would have been generally accepted by scientific men. But the cause of the remarkable change of climate during those late Tertiary and post-Tertiary times known as the glacial period is still without a completely satisfactory explanation. In Belt's day geologists were inclined to get over the difficulty of accounting for the phenomena by any feasible terrestrial change by explaining them as the result of cosmical causes, and Croll's theory of the increase of the eccentricity of the earth's orbit was widely received among them. Belt, on the other hand, held that the cold was due to an increase in the obliquity of the ecliptic. But these astronomical explanations have not met with much acceptance by physicists; and so chemists have been turned to by some geologists for support of the hypothesis of the variation in the amount of carbon dioxide in the air, or of other alterations in the atmosphere, while others have gone back to the idea of geographical changes. That considerable oscillations of the relative levels of land and sea took place during the Ice Age has been now clearly established, and the general result of the investigations favours Belt's opinion that the land during part of that period stood much higher than now over the northern regions of Europe and North America. It would, however, lead us too far away from the present book to enter into even a cursory examination of his views upon the glacial period, and those readers who desire to pursue the matter will find assistance for doing so in the bibliography at the end of this Introduction.
Of more immediate interest to us are the "observations on animals and plants in reference to the theory of evolution of living forms" which the title-page announces as a part of the narrative, and which indeed form the main portion of the work. Upon the publication of Darwin's "Origin of Species" in 1859, Belt had become an ardent evolutionist, and was henceforth always on the look-out for facts in support of the theories which had breathed such new life into biological studies. In Nicaragua he devoted special attention to those wonderful protective resemblances, especially among insects, which Bates had explained by his theory of "Mimicry;" and as the subject crops up again and again in this book, the non-scientific reader will find it helpful to have before him an outline of the expanded and completed theory—though he should be warned that some writers have been too much inclined to attribute to "mimicry" any accidental resemblance between two species. How far such accidental resemblances may be carried is probably well illustrated by the bee, the spider, and the fly orchis of our own downs and copses.
"Mimicry" proper is often confused with "protective resemblance," and it will be advisable to begin with the consideration of the latter.
Concealment, while useful at times to all animals, is absolutely essential to some; and it is wonderful in what different ways it is attained. In cases of "cryptic resemblance to surroundings" the shape, colouration, or markings are such as to conceal an animal by rendering it difficult to distinguish from its immediate environment. In most cases the effect is PROTECTIVE; but in snakes, spiders, mantids, and other preying animals it is termed AGGRESSIVE, since it enables these animals to stalk their prey undetected. It is probable that this power, when possessed by a vertebrate animal, nearly always bears the double meaning, as in the green tree frog, where the colouration is protective so far as it provides concealment from snakes, which are particularly fond of these frogs, and aggressive in that it allows flies and other insects to approach without suspicion.
There may be either General Resemblance to surrounding objects or Special Resemblance to definite objects. The plain sandy colour of desert animals, the snow white of the inhabitants of the arctic regions, the inconspicuous hues of nocturnal animals, the stripes of the tiger and the zebra, the spots of the leopard and the giraffe have all a cryptic effect which at a very short distance renders the creatures invisible amid their natural surroundings. Nor is it necessary in order to attain this invisibility that the colouring should be really dull and plain. It all depends upon the habitat. Mr. Wallace has described "a South American goatsucker which rests in the bright sunshine on little bare rocky islets in the upper Rio Negro where its unusually light colours so closely resemble those of the rock and sand that it can scarcely be detected till trodden upon." A little observation will supply large numbers of instances of such protective colouration.
It is, however, in the insect world that this principle of adaptation of animals to their environment is most fully and strikingly developed. "There are thousands of species of insects," says Mr. Wallace again, "which rest during the day clinging to the bark of dead or fallen trees; and the greater portion of these are delicately mottled with grey and brown tints, which though symmetrically disposed and infinitely varied, yet blend so completely with the usual colours of the bark, that at two or three feet distance they are quite undistinguishable."
In protective resemblances at their highest state of perfection the colouring is not constant but, as Professor Poulton puts it in his delightful book on "The Colours of Animals", "can be adjusted to harmonise with changes in the environment or to correspond with the differences between the environment of different individuals." The seasonal change of colour in northern animals is a well-known instance of the former, and the chameleon's alterations of hue of the latter.
Besides General Resemblance, in which the general effects of surrounding colours are reproduced, we have Special Resemblance, in which the appearance of a particular object is copied in shape and outline as well as in colour. Numerous instances will be found in this book, and a "Leaf Insect" and a "Moss Insect" are illustrated. But the classic example is the butterfly from the East Indies so graphically described by Mr. Wallace, Kallima paralekta, which always rests among dead or dry leaves and has itself leaf-like wings spotted over with specks to imitate the tiny fungi growths on the foliage it resembles. "It sits on a nearly upright twig, the wings fitting closely back to back, concealing the antennae and head, which are drawn up between their bases. The little tails of the hind wings touch the branch and form a perfect stalk to the leaf, which is supported in its place by the claws of the middle pair of feet which are slender and inconspicuous. The irregular outline of the wings gives exactly the perspective effect of a shrivelled leaf." The wonderful "stick insects" in like manner mimic the twigs of the trees among which they lurk. Nor need we go abroad in search of examples, for among our own insects are countless instances of marvellous resemblances to the inanimate or vegetable objects upon which they rest. One of the most interesting is that of the geometer caterpillars, which are very plentiful, and any one can observe them for himself even in a London garden. They support themselves for hours by means of their posterior legs, forming an angle of various degrees with the branch on which they are standing and looking for all the world like one of its twigs. The long cylindrical body is kept stiff and immovable, with the separations of the segments scarcely visible, and its colour is obscure and similar to that of the bark of the tree. Kirby and Spence tell of a gardener mistaking one of these caterpillars for a dead twig, and starting back in great alarm when, on attempting to break it off, he found it was a living animal.
Sometimes concealment is secured by the aid of adventitious objects. Many lepidopterous larvae live in cases made of the fragments of the substances upon which they feed; and certain sea-urchins cover themselves so completely with pebbles, shells, and so forth, that one can see nothing but a heap of little stones. Perhaps, however, the most interesting instance is the crab described by Mr. Bateson, which "takes a piece of weed in his two chelae and, neither snatching nor biting it, deliberately tears it across, as a man tears paper with his hands. He then puts one end of it into his mouth, and after chewing it up, presumably to soften it, takes it out in the chelae and rubs it firmly on his head or legs until it is caught by the peculiar curved hairs which cover them. If the piece of weed is not caught by the hairs, the crab puts it back in his mouth and chews it up again. The whole proceeding is most human and purposeful."
There is another class of colours in which not concealment but conspicuousness is the object aimed at. Such colours are borne by animals provided with formidable weapons of defence (the sting of the wasp, for example), or possessed of an unpleasant taste or offensive odour, and their foes come by experience to associate this form of colouring with disagreeable qualities and avoid the animals so marked. Belt was the first to account, in this way, for the conspicuous colouration of the skunk; and it is now believed that startling colours and conspicuous attitudes are intended to assist the education of enemies by enabling them to learn and remember the animals which are to be avoided. The explanation of warning colours was devised by Mr. Wallace to account for the brilliancy in the tints of certain caterpillars which birds find disagreeable, and the subject has been principally studied by experiments upon such caterpillars. But examples of warning colours are recognised, among many others, in the contrasted black and yellow of wasps, bees, and hornets, the bright red, black, and yellow bands of the deadly coral snakes, and the brilliantly coloured frog of Santo Domingo which hops unconcernedly about in the daytime in his livery of red and blue—"for nothing will eat him he well doth know."
But—and here comes in the principle to which the term "mimicry" is now restricted—if warning colours are helpful to noxious animals, then defenceless animals acquiring these colours will share in the protection afforded by them. And so we find a deceptive similarity between animals occurring in the same district, but not closely related, in which the mimicked form is unpalatable or has an odour repulsive to birds and lizards. It must, of course, be understood that the mimicry is unconscious, the result, as in the cases of cryptic resemblance, having been brought about by natural selection—the less perfect the mimicry the more liable are the individuals to be attacked, and the less chance have they of reproducing their kind.
This imitation was first accounted for by Mr. Bates in the case of the Heliconidae, a group of showy, slow-flying abundant butterflies possessing "a strong pungent semi-aromatic or medicinal odour which seems to pervade all the juices of their system." It does not follow, of course, that what seems to us a disagreeably smelling fluid should prove distasteful to the palate of a lizard or a bird. But careful observation of the butterflies convinced both Bates and Wallace that they were avoided, or at any rate not pursued, by birds and other creatures; and Belt found that they were rejected by his tame monkey which was very fond of other insects. So their conspicuous wings, with spots and patches of yellow, red, or white upon a black, blue or brown ground, may fairly be considered an example of warning colouration—though Mr. Thayer has with great ingenuity and acumen endeavoured to show that the markings are effective for concealment and that their value as warning marks is doubtful. Now, says Mr. Beddard, "in the same situations as those in which the Heliconias are found there also occur, more rarely, specimens of butterflies minutely resembling the Heliconias, but belonging to a perfectly distinct family—the Pieridae. They belong to the two genera Leptalis and Euterpe, consisting of numerous species, each of which shows a striking likeness to some one particular species of Heliconia. This likeness is not a mark of near affinity; it affects no important character, but only the shape and colouration of the wings."
The particular resemblance here described was the origin of the theory of Protective Mimicry, the conditions under which it occurs being, according to Mr. Wallace:
1. That the imitative species occur in the same area and occupy the same station as the imitated. 2. That the imitators are always the more defenceless. 3. That the imitators are also less numerous in individuals. 4. That the imitators differ from the bulk of their allies. 5. That the imitation, however minute, is external and visible only, never extending to internal characters or to such as do not affect the external appearance.
There are plenty of examples of this phenomenon, such as the hornet-like moths and bee-like flies of our own country, and many other instances will be found in these pages. One discovered in tropical America by Mr. W.L. Sclater would have much delighted Belt had he come across it. In that region of the world the leaf-cutting ants present a very characteristic appearance as the column proceeds homewards, each ant carrying a piece of leaf held vertically in its jaws; and a homopterous insect has been found that faithfully resembles an ant bearing its burden. The latter is suggested by the thin compressed green body of the insect, and its profile is precisely like that of the jagged edge of the fragment of leaf held over the back of the ant.
Of all the Nicaraguan fauna, judging from the narrative, the ants occupy the most prominent position. Both indoors and out they are ever in evidence. Belt describes the foraging ants, which do not make regular nests of their own, but attack those of other species and prey upon every killable living thing that comes in their way; the leaf-cutting ants, whose attacks upon his garden were repelled with so much difficulty; standing armies of ants maintained by certain trees for their protection, and many other kinds, some of which kept his attention constantly on the stretch. Much space is devoted to their habits and wonderful instincts, amounting in many cases, so Belt considered, to as clear an evidence of reasoning intelligence as can be claimed for man himself. Indeed, after reading the account of their freeing of an imprisoned comrade and their grappling with problems arising out of such modern inventions as carbolic acid and tramways, we need not feel surprised if an observer accustomed to scrutinise the animal world so closely feels sceptical on the subject of "instinct" viewed as a mysterious entity antithetically opposed to "reason" and supposed to act as its substitute in the lower orders.
In reference to their methods of obtaining food, ants have been classified as hunting, pastoral, and agricultural, "three types," as Lord Avebury remarks, "offering a curious analogy to the three great phases in the history of human development." As regards their social condition they differ from mankind in having successfully established communism. At the present day all the social hymenoptera possess a unique interest on account of their working-order or neuters. These, as is well-known, are females whose normal development has been checked. Are we to assume that "once upon a time" a woman's rights movement sprang up in bee-hives and ant-hills which ended in reducing the males to a very unimportant position and in limiting the number of the fully developed females? Are we to expect that the "strong-minded" women arising among us are the forerunners of a "neuter" order and the heralds of a corresponding change in human society?
"It is full of theories," says the author, writing of his book; modestly adding, "I trust not unsupported by facts." And so naturally does he dovetail the two together that the theories often seem portions of the facts. On all kinds of subjects suggestive reasons are proposed:—why the scarlet-runners which flowered so profusely in his garden never produced a single pod; why the banana and sugar-cane are probably not indigenous to America; why gold veins grow poorer as they descend into the earth; why whirlwinds rotate in opposite directions in the two hemispheres; why the earthenware vessels of the Indians are rounded at the bottom and require to be placed in a little stand—on all the varied matters that come under his observant eyes he has something interesting to say. You learn how the natives obtain sugar, palm-wine, and rubber; what is the use of the toucan's huge beak, and how plants secure the fertilisation of their flowers. You watch the tricks of the monkey, the humming-bird's courtship, the lying in wait of the alligator, and all the ceaseless activity of the forest—that forest so monotonous in its general features, but fascinating beyond measure when the varied life-histories working out within it are realised—and you share in the keen joy of the naturalist who has written with such simple eloquence of the beauty, the wonder, and the mystery of the natural world.
A.B.
The following is a list of the works of Thomas Belt:—
An inquiry into the Origin of Whirlwinds, Philosophical Magazine volume 17 1859 pages 47-53. Mineral Veins: an Inquiry into their Origin founded on a Study of the Auriferous Quartz Veins of Australia, London 1861. On some Recent Movements of the Earth's Surface and their Geological Bearings [1863] Nova Scotian Institute of Natural Science Proceedings and Transactions volume 1 part 1 1867 pages 19-30. List of Butterflies observed in the Neighbourhood of Halifax, Nova Scotia [1863] Nova Scotian Institute of Natural Science Proceedings and Transactions volume 2 part 1 1867 pages 87-92. On the Formation and Preservation of Lakes by Ice Action, Geological Society Quarterly Journal volume 20 1864 pages 463-465, Philosophical Magazine volume 28 1864 page 323, Nova Scotian Institute of Natural Science Proceedings and Transactions volume 2 part 3 1867 page 70. The Glacial Period in North America [1866] Nova Scotian Institute of Natural Science Proceedings and Transactions volume 2 part 4 1867 pages 91-106. On some New Trilobites from the Upper Cambrian Rocks of North Wales, Geological Magazine volume 4 1867 pages 294-295. On the "Lingula Flags" or "Festiniog Group" are the Dolgelly District, Geological Magazine volume 4 1867 pages 493-495, 536-543; volume 5 1868 pages 5-11. The Naturalist in Nicaragua, London 1874 2nd edition revised and corrected 1888. Glacial Phenomena in Nicaragua, American Journal of Science volume 7 1874 pages 594-595. An Examination of the Theories that have been proposed to account for the Climate of the Glacial Period, Journal of Science volume 4 1874 pages 421-464. The Steppes of Siberia, Geological Society Quarterly Journal volume 30 1874 pages 490-498, Geological Magazine Decade 2 volume 1 1874 pages 423-424. The Glacial Period, Nature volume 10 1874 pages 25-26. Niagara: Glacial and Post-Glacial Phenomena, Journal of Science volume 5 1875 pages 135-156. The Drift of Devon and Cornwall: its Origin, Correlation with that of the South-West of England, and Place in the Glacial Series, Geological Society Quarterly Journal volume 32 1876 pages 80-90; Geological Magazine volume 2 1875 pages 622-624, Philosophical Magazine volume 1 1876 pages 159-161. On the Geological Age of the Deposits containing Flint Implements at Hoxne, in Suffolk, and the Relation that Palaeolithic Man bore to the Glacial Period, Journal of Science volume 6 1876 pages 289-304. On the First Stages of the Glacial Period in Norfolk and Suffolk, Geological Magazine volume 4 1877 pages 156-158. The Steppes of Southern Russia, Geological Society Quarterly Journal volume 33 1877 pages 843-862; Philosophical Magazine volume 4 1877 pages 151-152. On the Loess of the Rhine and the Danube, Journal of Science volume 7 1877 pages 67-90. The Glacial Period in the Southern Hemisphere, Journal of Science volume 7 1877 pages 326-353. Quartzite Implements at Brandon, Nature volume 16 1877 page 101. On the Discovery of Stone Implements in Glacial Drift in North America, Journal of Science volume 8 1878 pages 55-74. The Superficial Gravels and Clays around Finchley, Ealing, and Brentford, Journal of Science volume 8 1878 pages 316-360. Notes on the Discovery of a Human Skull in the Drift near Denver, Colorado, Proceedings of the American Association for the Advancement of Science at St. Louis, Missouri August 1878 volume 27 (1879) pages 298-299.
[The notes within square brackets have been added to this edition by the writer of the Introduction. ]
[Title-page of the First Edition.]
THE
NATURALIST IN NICARAGUA
A NARRATIVE OF
A RESIDENCE AT THE GOLD MINES OF CHONTALES;
JOURNEYS IN THE SAVANNAHS AND FORESTS;
With Observations of Animals and Plants in Reference to the Theory of Evolution of Living Forms.
BY THOMAS BELT, F.G.S.
AUTHOR OF "MINERAL VEINS," "THE GLACIAL PERIOD IN NORTH AMERICA," ETC. ETC.
"It was his faith—perhaps is mine— That life in all its forms is one, And that its secret conduits run Unseen, but in unbroken line, From the great fountain-head divine, Through man and beast, through grain and grass."
LONGFELLOW.
[Dedication of the First Edition.]
TO
HENRY WALTER BATES,
WHOSE ADMIRABLE WORK,
"THE NATURALIST ON THE RIVER AMAZONS,"
HAS BEEN MY GUIDE AND MODEL,
I DEDICATE THIS BOOK,
AS A TOKEN OF RESPECT AND FRIENDSHIP.
(SKETCH MAP OF NICARAGUA.)
CONTENTS.
INTRODUCTION.
CHAPTER 1.
Arrival at Greytown.—The river San Juan.—Silting up of the harbour.—Crossing the bar.—Lives lost on it.—Sharks. —Christopher Columbus.—Appearance of the town.—Trade. —Healthiness of the town and its probable cause.—Comparison between Greytown, Pernambuco, and Maceio.—Wild fruits.—Plants. —Parrots, toucans, and tanagers.—Butterflies and beetles. —Mimetic forms.—Alligators: boy drowned at Blewfields by one. —Their method of catching wild pigs.
CHAPTER 2.
Commence journey up San Juan river.—Palms and wild canes. —Plantations.—The Colorado river.—Proposed improvement of the river.—Progress of the Delta.—Mosquitoes.—Disagreeable night. —Fine morning.—Vegetation of the banks.—Seripiqui river. —Mot-mots.—Foraging ants: their method of hunting.—Ant-thrushes. —They attack the nests of other ants.—Birds' nests, how preserved from them.—Reasoning powers in ants.—Parallel between the mammalia and the hymenoptera.—Utopia.
CHAPTER 3.
Journey up river continued.—Wild pigs and jaguar.—Bungos.—Reach Machuca.—Castillo.—Capture of Castillo by Nelson.—India-rubber trade.—Rubber-men.—Method of making india-rubber.—Congo monkeys. —Macaws.—The Savallo river.—Endurance of the boatmen.—San Carlos.—Interoceanic canal.—Advantages of the Nicaraguan route. —The Rio Frio.—Stories about the wild Indians.—Indian captive children.—Expeditions up the Rio Frio.—American river steamboats.
CHAPTER 4.
The lake of Nicaragua.—Ometepec.—Becalmed on the lake.—White egrets.—Reach San Ubaldo.—Ride across the plains.—Vegetation of the plains.—Armadillo.—Savannahs.—Jicara trees.—Jicara bowls. —Origin of gourd-shaped pottery.—Coyotes.—Mule-breeding.—Reach Acoyapo.—Festa.—Cross high range.—Esquipula.—The Rio Mico. —Supposed statues on its banks.—Pital.—Cultivation of maize. —Its use from the earliest times in America.—Separation of the maize-eating from the mandioca-eating indigenes of America. —Tortillas.—Sugar-making.—Enter the forest of the Atlantic slope.—Vegetation of the forest.—Muddy roads.—Arrive at Santo Domingo.
CHAPTER 5.
Geographical position of Santo Domingo.—Physical geography.—The inhabitants.—Mixed races.—Negroes and Indians compared.—Women. —Establishment of the Chontales Gold-Mining Company.—My house and garden.—Fruits.—Plantains and bananas; probably not indigenous to America: propagated from shoots: do not generally mature their seeds.—Fig-trees.—Granadillas and papaws.—Vegetables. —Dependence of flowers on insects for their fertilisation.—Insect plagues.—Leaf-cutting ants: their method of defoliating trees: their nests.—Some trees are not touched by the ants.—Foreign trees are very subject to their attack.—Method of destroying the ants.—Migration of the ants from a nest attacked.—Corrosive sublimate causes a sort of madness amongst them.—Indian plan of preventing them ascending young trees.—Leaf-cutting ants are fungus-growers and eaters.—Sagacity of the ants.
CHAPTER 6.
Configuration of the ground at Santo Domingo.—Excavation of valleys.—Geology of the district.—Decomposition of the rocks. —Gold-mining.—Auriferous quartz veins.—Mode of occurrence of the gold.—Lodes richer next the surface than at lower depths. —Excavation and reduction of the ore.—Extraction of the gold.— "Mantos".—Origin of mineral veins: their connection with intrusions of Plutonic rocks.
CHAPTER 7.
Climate of the north-eastern side of Nicaragua.—Excursions around Santo Domingo.—The Artigua.—Corruption of ancient names. —Butterflies, spiders, and wasps.—Humming-birds, beetles, and ants.—Plants and trees.—Timber.—Monkey attacked by eagle. —White-faced monkey.—Anecdotes of a tame one.—Curassows and other game birds.—Trogons, woodpeckers, mot-mots, and toucans.
CHAPTER 8.
Description of San Antonio valley.—Great variety of animal life. —Pitcher-flowered Marcgravias.—Flowers fertilised by humming-birds.—By insects.—Provision in some flowers to prevent insects, not adapted for carrying the pollen, from obtaining access to the nectaries.—Stories about wasps.—Humming-birds bathing. —Singular myriapods.—Ascent of Pena Blanca.—Tapirs and jaguars. —Summit of Pena Blanca.
CHAPTER 9.
Journey to Juigalpa.—Description of Libertad.—The priest and the bell.—Migratory butterflies and moths.—Indian graves.—Ancient names.—Dry river-beds.—Monkeys and wasps.—Reach Juigalpa.—Ride in neighbourhood.—Abundance of small birds.—A poor cripple.—The "Toledo."—Trogons.—Waterfall.—Sepulchral mounds.—Broken statues.—The sign of the cross.—Contrast between the ancient and the present inhabitants.—Night life.
CHAPTER 10.
Juigalpa.—A Nicaraguan family.—Description of the road from Juigalpa to Santo Domingo.—Comparative scarcity of insects in Nicaragua in 1872.—Water-bearing plants.—Insect-traps.—The south-western edge of the forest region.—Influence of cultivation upon it.—Sagacity of the mule.
CHAPTER 11.
Start on journey to Segovia.—Rocky mountain road.—A poor lodging. —The rock of Cuapo.—The use of large beaks in some birds. —Comoapa.—A native doctor.—Vultures.—Flight of birds that soar. —Natives live from generation to generation on the same spot.—Do not give distinctive names to the rivers.—Caribs barter guns and iron pots for dogs.—The hairless dogs of tropical America. —Difference between artificial and natural selection.—The cause of sterility between allied species considered.—The disadvantages of a covering of hair to a domesticated animal in a tropical country.
CHAPTER 12.
Olama.—The "Sanate."—Muy-muy.—Idleness of the people.—Mountain road.—The "Bull Rock."—The bull's-horn thorn.—Ants kept as standing armies by some plants.—Use of honey-secreting glands. —Plant-lice, scale-insects, and leaf-hoppers furnish ants with honey, and in return are protected by the latter.—Contest between wasps and ants.—Waxy secretions of the homopterous hemiptera.
CHAPTER 13.
Matagalpa.—Aguardiente.—Fermented liquors of the Indians.—The wine-palm.—Idleness of the Nicaraguans.—Pine and oak forests. —Mountain gorge.—Jinotega.—Native plough.—Descendants of the buccaneers.—San Rafael.—A mountain hut.
CHAPTER 14.
Great range composed of boulder clay.—Daraily.—Lost on the savannahs.—Jamaily.—A deer-hunter's family.—Totagalpa.—Walls covered with cement and whitewashed.—Ocotal.—The valley of Depilto.—Silver mine.—Geology of the valley.—Glacial drift.—The glacial period in Central America.—Evidence that the ice extended to the tropics.—Scarcity of gold in the valley gravels. —Difference of the Mollusca on the east and west coast of the Isthmus of Darien.—The refuge of the tropical American animals and plants during the glacial period.—The lowering of the sea-level. —The land shells of the West Indian Islands.—The Malay Archipelago.—Easter Island.—Atlantis.—Traditions of the deluge.
CHAPTER 15.
A Nicaraguan criminal.—Geology between Ocotal and Totagalpa. —Preparations at Totagalpa for their annual festival. —Chicha-drinking.—Piety of the Indians.—Ancient civilisation of tropical America.—Palacaguina.—Hospitality of the Mestizos. —Curious custom at the festival at Condego.—Cross range between Segovia and Matagalpa.—Sontuli.—Birds' nests.
CHAPTER 16.
Concordia.—Jinotega.—Indian habits retained by the people. —Indian names of towns.—Security of travellers in Nicaragua. —Native flour-mill.—Uncomfortable lodgings.—Tierrabona.—Dust whirlwind.—Initial form of a cyclone.—The origin of cyclones.
CHAPTER 17.
Cattle-raising.—Don Filiberto Trano's new house.—Horse-flies and wasps.—Teustepe.—Spider imitating ants.—Mimetic species. —Animals with special means of defence are conspicuously marked, or in other ways attract attention.—Accident to horse.—The "Mygale."—Illness.—Conclusion of journey.
CHAPTER 18.
Division of Nicaragua into three zones.—Journey from Juigalpa to lake of Nicaragua.—Voyage on lake.—Fresh-water shells and insects.—Similarity of fresh-water productions all over the world. —Distribution of European land and fresh-water shells.—Discussion of the reasons why fresh-water productions have varied less than those of the land and of the sea.
CHAPTER 19.
Iguanas and lizards.—Granada.—Politics.—Revolutions.—Cacao cultivation.—Masaya.—The lake of Masaya.—The volcano of Masaya. —Origin of the lake basin.
CHAPTER 20.
Indian population of the country lying between the great lakes of Nicaragua and the Pacific.—Discovery and conquest of Nicaragua by the Spaniards.—Cruelties of the Spaniards.—The Indians of Western Central America all belonged to one stock.—Decadence of Mexican civilisation before the arrival of the Spaniards.—The designation "Nahuatls" proposed to include all the Mexican, Western Central American, and Peruvian races that had descended from the same ancient stock.—The Nahuatls distinct from the Caribs on one side and the Red Indians on the other.—Discussion of the question of the peopling of America.
CHAPTER 21.
Return to Santo Domingo.—The birds of Chontales.—The insects of Chontales.—Mimetic forms.—Departure from the mines.—Nicaragua as a field for emigration.—Journey to Greytown.—Return to England.
INDEX.
. . .
LIST OF ILLUSTRATIONS.
PLATE 1. SKETCH MAP OF NICARAGUA.
PLATE 2. ALLIGATORS.
PLATE 3. HEADS OF MOT-MOTS.
PLATE 4. COMMISSIONER'S HOUSE AT SANTO DOMINGO.
PLATE 5. NEST OF LEAF-CUTTING ANT.
PLATE 6. MACHINERY OF CHONTALES GOLD-MINING COMPANY.
PLATE 7. SECTION OF MINE SHOWING METHOD OF EXTRACTING THE ORE.
PLATE 8. SECTION OF SAN ANTONIO LODE.
PLATE 9. HUMMING-BIRDS (Florisuga mellivora, LINN.).
PLATE 10. TONGUES OF HUMMING-BIRD AND WOODPECKER.
PLATE 11. PITCHER-FLOWER (Marcgravia nepenthoides).
PLATE 12. FLOWER OF THE "PALOSABRE."
PLATE 13. ADVENTURE WITH A JAGUAR.
PLATE 14. PENA BLANCA.
PLATE 15. INDIAN STATUES.
PLATE 16. PATH UP STEEP HILL.
PLATE 17. QUISCALUS.
PLATE 18. BULL'S-HORN THORN.
PLATE 19. LEAF OF MELASTOMA.
PLATE 20. NATIVE STILL.
PLATE 21. NATIVE PLOUGH.
PLATE 22. GEOLOGICAL SECTION NEAR OCOTAL.
PLATE 23. HORNET AND MIMETIC BUG.
PLATE 24. GEOLOGICAL SECTION AT MASAYA.
PLATE 25. LONGICORN BEETLES OF CHONTALES.
PLATE 26. LEAF INSECT.
PLATE 27. MOSS INSECT.
. . .
PREFACE TO THE FIRST EDITION.
The following pages have been written in the intervals between arduous professional engagements. Begun on the Atlantic during my voyage home from Central America, the first half relieved the tedium of a long and slow recovery from the effects of an accident occurring on board ship. The middle of the manuscript found me traversing the high passes of the snow-clad Caucasus, where I made acquaintance with the Abkassians, in whose language Mr. Hyde Clark finds analogies with those of my old friends the Brazilian Indians. I now write this brief preface and the last chapter of my book (with Bradshaw's "Continental Guide" as my only book of reference), on my way across the continent to the Urals, and beyond, to the country of the nomad Kirghizes and the far Altai mountains on the borders of Tibet; and when readers receive my work I shall probably have turned my face homewards again, and for weeks be speeding across the frozen Siberian steppes, wrapped in furs, listening to the sleigh bells, and wondering how my book has sped. It is full of theories—I trust not unsupported by facts: some thought out on the plains of Southern Australia; some during many a solitary sleigh drive over frozen lakes in North America; some in the great forests of Central and South America; some on the wide ocean, with the firmament above and below blending together on the horizon; and some, again, in the bowels of the earth when seeking for her hidden riches. The thoughts are those of a lifetime compressed into a little book; and, like the genie of the Arabian tale, imprisoned in an urn, they may, when it is opened, grow and magnify, or, on the contrary, be kicked back into the sea of oblivion.
This much is necessary; not to disarm criticism, but to excuse myself to those authors whose labours on some of the subjects I have treated of I may not have mentioned. I have, during my sojourns in England, worked hard to read up the literature of the various questions discussed, but I know there must be many oversights and omissions in referring to what others have done; especially with regard to continental writers, for I know no language but my mother-tongue; and their works, excepting where I have had access to translations, have been sealed books to me.
I am indebted to Mr. H.W. Bates for much assistance, and especially for undertaking the superintendence of these sheets in their passage through the press; to Mr. W.C. Hewitson, of Oatlands Park, I am under many obligations, for taking charge of my entomological collections, for naming many of my butterflies, and for access to his magnificent collection of Diurnal Lepidoptera. Mr. Osbert Salvin and Dr. P.L. Sclater have named for me my collection of birds; and for much entomological information I am indebted to Professor Westwood, Mr. F. Smith, and Dr. D. Sharp; whilst, in botany, Professor D. Oliver, of Kew, has kindly named for me some of the plants. Through the assistance of these eminent authorities, I trust that the scientific names scattered throughout the book may be depended upon as correct.
Nijni Novgorod,
October 9th, 1873.
THE NATURALIST IN NICARAGUA.
CHAPTER 1.
Arrival at Greytown. The river San Juan. Silting up of the harbour. Crossing the bar. Lives lost on it. Sharks. Christopher Columbus. Appearance of the town. Trade. Healthiness of the town and its probable cause. Comparison between Greytown, Pernambuco, and Maceio. Wild fruits. Plants. Parrots, toucans, and tanagers. Butterflies and beetles. Mimetic forms. Alligators. Boy drowned at Blewfields by an alligator. Their method of catching wild pigs.
At noon on the 15th February 1868, the R.M.S.S. "Solent," in which I was a passenger, anchored off Greytown, or San Juan del Norte, the Atlantic port of Nicaragua in Central America. We lay about a mile from the shore, and saw a low flat coast stretching before us. It was the delta of the river San Juan, into which flows the drainage of a great part of Nicaragua and Costa Rica, and which is the outlet for the waters of the great lake of Nicaragua. Its watershed extends to within a few miles of the Pacific, for here the isthmus of Central America, as in the great continents to the north and south of it, sends off by far the largest portion of its drainage to the Atlantic. In the rainy season the San Juan is a noble river, and even in the dry months, from March to June, there is sufficient water coming down from the lake to keep open a fine harbour, if it were not that about twenty miles above its mouth it begins to dissipate its force by sending off a large branch called the Colorado river, and lower down parts with more of its waters by side channels. Twenty years ago the main body of water ran past Greytown; there was then a magnificent port, and large ships sailed up to the town, but for several years past the Colorado branch has been taking away more and more of its waters, and the port of Greytown has in consequence silted up. All ships now have to lie off outside, and a shallow and, in heavy weather, dangerous bar has to be crossed.* [* Greytown is still the headquarters of Nicaraguan trade with Europe and Eastern America though the attempts to improve the harbour by dredging and building jetties have had only partial success. Its great opportunity passed with the final abandonment, in favour of the Panama route, of the scheme for an inter-oceanic canal by way of the lakes, with its eastern terminus a mile to the north of the town at a spot which was named "America."]
All we could see from the steamer was the sandy beach on which the white surf was breaking, a fringe of bushes with a few coco-nut palms holding up their feathery crowns, and in the distance a low background of dark foliage. Before we anchored a gun was fired, and in quick answer to the signal some canoes, paddled by negroes of the Mosquito coast, here called "Caribs," were seen crossing the bar, and in a few minutes were alongside. Getting into one of the canoes with my boxes, I was rapidly paddled towards the shore. When we reached the bar we were dexterously taken over it—the Caribs waited just outside until a higher wave than usual came rolling in, then paddling with all their might we were carried over on its crest, and found ourselves in the smooth water of the river.
Many lives have been lost on this bar. In 1872 the commander of the United States surveying expedition and six of his men were drowned in trying to cross it in heavy weather. Only a few mangled remnants of their bodies were ever found; for what adds to the horror of an upset at this place, and perhaps has unnerved many a man at a critical moment, is that large sharks swarm about the entrance to the river. We saw the fin of one rising above the surface of the water as it swam lazily about, and the sailors of the mail steamers when lying off the port often amuse themselves by catching them with large hooks baited with pieces of meat. It is probable that it was at one of the mouths of the San Juan that Columbus, in his fourth voyage, lost a boat's crew who had been sent for wood and fresh water, and when returning were swamped on the bar. Columbus had rounded Cape Gracias a Dios four days before, and had sailed down the coast with a fair wind and tide, so that he might easily have reached the San Juan.
Inside the bar we were in smooth water, for but a small stream is discharged by this channel. On our right was a sandy beach, on our left great beds of grass growing out of the shoal water—weedy banks filled up the once spacious harbour, and cattle waded amongst the long grass, where within the last twenty years a frigate has lain at anchor. Wading and aquatic birds were abundant in the marshes, amongst which white cranes and a chocolate-brown jacana, with lemon-yellow under wing, were the most conspicuous. A large alligator lazily crawled off a mud-spit into the water, where he floated, showing only his eyes and the pointed scales of his back above the surface. The town was now in full view—neat, white-painted houses, with plume-crowned palms rising amongst and over them, and we landed at one of several wooden wharves that jut into the river.
Greytown, though only a small place, is one of the neatest tropical towns that I have visited. The houses, especially in the business portion of the town, are well built of wood, and painted white with brown roofs. Pretty flower gardens surround or front many of them. Others are nearly hidden amongst palms and bread-fruit, orange, mango, and other tropical fruit trees. A lovely creeper (Antigonon leptopus), with festoons of pink and rose-coloured flowers, adorns some of the gardens. It is called la vegessima, "the beautiful," by the natives, and I found it afterwards growing wild in the provinces of Matagalpa and Segovia, where it was one of the great favourites of the flower-loving Indians. The land at and around Greytown is perfectly level. The square, the open spaces, and many of the streets are covered with short grass that makes a beautiful sward to walk on.
The trade in the town is almost entirely in the hands of foreign residents, amongst whom Mr. Hollenbeck, a citizen of the United States, is one of the most enterprising. A considerable import trade is done with the States and England. Coffee, indigo, hides, cacao, sugar, logwood, and india-rubber are the principal exports. I called on Dr. Green, the British Consul, and found him a most courteous and amiable gentleman, ready to afford protection or advice to his countrymen, and on very friendly terms with the native authorities. He has lived for many years in Nicaragua, and his many charitable kindnesses, and especially the medical assistance that he renders in all cases of emergency, free of charge, have made him very popular at Greytown. His beautiful house and grounds, with a fine avenue of coco-nut trees in full bearing, form one of the most attractive sights in Greytown. I found Mr. Paton, the vice-consul, equally obliging, and I am indebted to him for much information respecting the trade of the port, particularly with regard to the export of india-rubber, the development of which trade he was one of the first to encourage.
Behind the town there is a long lagoon, and for several miles back the land is quite level, and interspersed with lakes and ponds with much marshy ground. Perfectly level, surrounded by swamps, and without any system of drainage, either natural or artificial, excepting such as the sandy soil affords, Greytown might be thought a very unhealthy site for a town. Notwithstanding, however, its apparent disadvantages, and that for nine months of the year it is subject to heavy tropical rains, it is comparatively healthy, and freer from fever than many places that appear at first sight better situated. Much is due to the porous sandy soil, but more I believe to what appears at first sight an element of danger, the perfect flatness of the ground. Where there are hills there must be hollows, and in these the air stagnates; whilst here, where the land is quite level, the trade winds that blow pretty constantly find their way to every part, and carry off the emanations from the soil. As a similar instance I may mention the city of Pernambuco, on the eastern coast of Brazil, containing 80,000 inhabitants. It is perfectly level like Greytown, surrounded and intersected with channels of water, above the level of which it only stands a few feet. The crowded parts of the town are noted for their evil smells and filth, but, though entirely without drainage, it is celebrated for its healthiness; whilst a little lower down the coast, the town of Maceio, situated about sixty feet above the sea, surrounded by undulating ranges and with a good natural drainage, is much more unhealthy, fevers being very prevalent. As at Greytown so at Pernambuco, the trade winds blow with much regularity, and there are neither hills nor hollows to interfere with the movements of the air, so that miasmatic exhalations cannot accumulate.
Surrounding the cleared portions around Greytown is a scrubby bush, amongst which are many guayava trees (Psidium sp.) having a fruit like a small apple filled with seeds, of a sub-acid flavour, from which the celebrated guava jelly is made. The fruit itself often occasions severe fits of indigestion, and many of the natives will not swallow the small seeds, but only the pulpy portion, which is said to be harmless. I saw another fruit growing here, a yellow berry about the size of a cherry, called "Nancito" by the natives. It is often preserved by them with spirit and eaten like olives. Beyond the brushwood, which grows where the original forest has been cut down, there are large trees covered with numerous epiphytes—Tillandsias, orchids, ferns, and a hundred others, that make every big tree an aerial garden. Great arums perch on the forks and send down roots like cords to the ground, whilst lianas run from tree to tree or hang in loops and folds like the disordered tackle of a ship.
Green parrots fly over in screaming flocks, or nestle in loving couples amidst the foliage, toucans hop along the branches, turning their long, highly-coloured beaks from side to side with an old-fashioned look, and beautiful tanagers (Ramphocaelus passerinii) frequent the outskirts of the forest, all velvety black, excepting a large patch of fiery-red above the tail, which renders the bird very conspicuous. It is only the male that is thus coloured, the female being clothed in a sober suit of greenish-brown. I think this bird is polygamous, for several of the brown ones were always seen with one of the red-and-black ones. The bright colours of the male must make it very conspicuous to birds of prey, and, probably in consequence, it is not nearly so bold as the obscurely-coloured females. When a clear space in the brushwood is to be crossed, such as a road, two or three of the females will fly across first, before the male will venture to do so, and he is always more careful to get himself concealed amongst the foliage than his mates.
I walked some distance into the forest along swampy paths cut by charcoal burners, and saw many beautiful and curious insects. Amongst the numerous butterflies, large blue Morphos and narrow, weak-winged Heliconidae, striped and spotted with yellow, red, and black, were the most conspicuous and most characteristic of tropical America. Amongst the beetles I found a curious longicorn (Desmiphora fasciculata), covered with long brown and black hairs, and closely resembling some of the short, thick, hairy caterpillars that are common on the bushes. Other closely allied species hide under fallen branches and logs, but this one clung exposed amongst the leaves, its antennae concealed against its body, and its resemblance to a caterpillar so great, that I was at first deceived by it. It is well known that insectivorous birds will not touch a hairy caterpillar, and this is only one of numberless instances where insects, that have some special protection against their enemies, are closely imitated by others belonging to different genera, and even different orders. Thus, wasps and stinging ants have hosts of imitators amongst moths, beetles, and bugs, and I shall have many curious facts to relate concerning these mimetic resemblances. To those not acquainted with Mr. Bates's admirable remarks on mimetic forms, I must explain that we have to speak of one species imitating another, as if it were a conscious act, only on account of the poverty of our language. No such idea is entertained, and it would have been well if some new term had been adopted to express what is meant. These deceptive resemblances are supposed, by the advocates of the origin of species by natural selection, to have been brought about by varieties of one species somewhat resembling another having special means of protection, and preserved from their enemies in consequence of that unconscious imitation. The resemblance, which was perhaps at first only remote, is supposed to have been increased in the course of ages by the varieties being protected that more and more closely approached the species imitated, in form, colour, and movements. These resemblances are not only between insects of different genera and orders, but between insects and flowers, leaves, twigs, and bark of trees, and between insects and inanimate nature. They serve often for concealment, as when leaves are imitated by leaf-insects and many butterflies, or for a disguise that enables predatory species to get within reach of their prey, as in those spiders that resemble the petals of flowers amongst which they hide.
(PLATE 1. ALLIGATORS IN SAN JUAN RIVER.)
That I may not travel over the same ground twice, I may here mention that on a subsequent visit to Greytown I rode a few miles northward along the beach. On my return, I tied up the horse and walked about a mile over the sand-bank that extends down to the mouth of the river. A long, deep branch forms a favourite resort for alligators. At the far end of a sand-spit, near where some low trees grew, I saw several dark objects lying close to the water on the shelving banks. They were alligators basking in the sun. As I approached, most of them crawled into the water. Mr. Hollenbeck had been down a few days before shooting at them with a rifle, to try to get a skull of one of the monsters, and I passed a dead one that he had shot. As I walked up the beach, I saw many that were not less than fifteen feet in length. One lay motionless, and thinking it was another dead one, I was walking up to it, and had got within three yards, when I saw the film over its eye moving; otherwise it was quite still, and its teeth projecting beyond its lips added to its intense ugliness and appearance of death. There was no doubt, however, about the movement of the eye-covers, and I went back a short distance to look for a stick to throw at it; but when I turned again, the creature was just disappearing into the water. It is their habit to lie quite still, and catch animals that come near them. Whether or not it was waiting until I came within the swoop of its mighty tail I know not, but I had the feeling that I had escaped a great danger. It was curious that it should have been so bold only a few days after Mr. Hollenbeck had been down shooting at them. There were not less than twenty altogether, and they swam out into the middle of the inlet and floated about, looking like logs in the water, excepting that one stretched up its head and gave a bellow like a bull. They sometimes kill calves and young horses, and I was told of one that had seized a full-grown horse, but its struggles being observed, some natives ran down and saved it from being pulled into the water and drowned. I heard several stories of people being killed by them, but only one was well authenticated. This was told me by the head of the excellent Moravian Mission at Blewfields, who was a witness of the occurrence. He said that one Sunday, after service at their chapel at Blewfields, several of the youths went to bathe in the river, which was rather muddy at the time; the first to plunge in was a boy of twelve years of age, and he was immediately seized by a large alligator, and carried along under water. My informant and others followed in a canoe, and ultimately recovered the body, but life was extinct. The alligator cannot devour its prey beneath the water, but crawls on land with it after he has drowned it. They are said to catch wild pigs in the forest near the river by half burying themselves in the ground. The pigs come rooting amongst the soil, the alligator never moves until one gets within its reach, when it seizes it and hurries off to the river with it. They are often seen in hot weather on logs or sand-spits lying with their mouths wide open. The natives say they are catching flies, that numbers are attracted by the saliva of the mouth, and that when sufficient are collected, the alligator closes its jaws upon them, but I do not know that any reliance can be placed on the story. Probably it is an invention to account for the animals lying with their mouths open; as in all half-civilised countries I have visited I have found the natives seldom admit they do not know the reason of anything, but will invent an explanation rather than acknowledge their ignorance.
CHAPTER 2.
Commence journey up San Juan river. Palms and wild canes. Plantations. The Colorado river. Proposed improvement of the river. Progress of the delta. Mosquitoes. Disagreeable night. Fine morning. Vegetation of the banks. Seripiqui river. Mot-mots. Foraging ants: their method of hunting. Ant-thrushes. They attack the nests of other ants. Birds' nests, how preserved from them. Reasoning powers in ants. Parallel between the Mammalia and the Hymenoptera. Utopia.
I FOUND at Greytown the mail-boat of the Chontales Gold-Mining Company, which came down monthly in charge of Captain Anderson, an Englishman who had knocked about all over the world. The crew consisted of four Mosquito negroes, who are celebrated on this coast for their skill as boatmen. Besides the crew, we were taking three other negroes up to the mines, and with my boxes we were rather uncomfortably crowded for a long journey. The canoe itself was made from the trunk of a cedar-tree (Cedrela odorata). It had been hollowed out of a single log, and the sides afterwards built up higher with planking. This makes a very strong boat, the strength and thickness being where it is most required, at the bottom, to withstand the thumping about amongst the rocks of the rapids. I was once in one, coming down a dangerous rapid on the river Gurupy, in Northern Brazil, when we were driven with the full force of the boiling stream broadside upon a rock, with such force that we were nearly all thrown down, but the strong canoe was uninjured, although no common boat could have withstood the shock.
Having determined to go up the river in this boat, we took provisions with us for the voyage, and one of the negroes agreed to act as cook. Having arranged everything, and breakfasted with my kind friends, Mr. and Mrs. Hollenbeck, I bade them adieu, and settled myself into the small space in the canoe that I expected to occupy for six days. Captain Anderson took the helm, the "Caribs" dipped their paddles into the water, and away we glided into a narrow channel amongst long grass and rushes that almost touched us on either side. Greytown, with its neat white houses, and feathery palms, and large-leaved bread-fruit trees, was soon shut from our view, and our boatmen plying their paddles with the greatest dexterity and force, made the canoe shoot along through the still water. Soon we emerged into a wider channel where a stronger stream was running, and then we coasted along close to the shore to avoid the strength of the current. The banks at first were low and marshy and intersected by numerous channels; the principal tree was a long, coarse-leaved palm, and there were great beds of wild cane and grass, amongst which we occasionally saw curious green lizards, with leaf-like expansions (like those on the leaf-insects), assimilating them in appearance to the vegetation amongst which they sought their prey. As we proceeded up the river, the banks gradually became higher and drier, and we passed some small plantations of bananas and plantains made in clearings in the forest, which now consisted of a great variety of dicotyledonous trees with many tall, graceful palms; the undergrowth being ferns, small palms, Melastomae, Heliconiae, etc. The houses at the plantations were mostly miserable thatched huts with scarcely any furniture, the owners passing their time swinging in dirty hammocks, and occasionally taking down a canoe-load of plantains to Greytown for sale. It is one of the rarest sights to see any of these squatters at work. Their plantain patch and occasionally some fish from the river suffice to keep them alive and indolent.
At seven o'clock we reached the Colorado branch, which carries off the greater part of the waters of the San Juan to the sea. This is about twenty miles above Greytown, but only eighteen by the Colorado to the sea, and is near the head of the delta, as I have already mentioned. The main body of water formerly flowed down past Greytown, and kept the harbour there open, but a few years ago, during a heavy flood, the river greatly enlarged and deepened the entrance to the Colorado Channel, and since then year by year the Greytown harbour has been silting up. Now (I am writing in 1873) there is twelve feet of water on the bar at the Colorado in the height of the dry season, whilst at Greytown the outlet of the river is sometimes closed altogether. The merchants at Greytown have entertained the project of dredging out the channel again, but now that the river has found a nearer way to the sea by the Colorado this would be a herculean task, and it would cost much less money to move the whole town to the Colorado, where by dredging the bar a fine harbour might easily be made, but unfortunately the Colorado is in Costa Rica, the Greytown branch in Nicaragua, and there are constant bickerings between the two states respecting the outlet of this fine river, which make any well-considered scheme for the improvement of it impracticable at present. A sensible solution of the difficulty would be a federation of the two small republics. The heads of the political parties in the two countries see, however, in this a danger to their petty ambitions, and will not risk the step, and so the boundary question remains an open one, threatening at any moment to plunge the two countries into an impoverishing war.
If the Colorado were not to be interfered with by man, it would, in the course of ages, carry down great quantities of mud, sand, and trunks of trees, and gradually form sandbanks at its mouth, pushing out the delta further and further at this point, until it was greatly in advance of the rest of the coast; the river would then break through again by some nearer channel, and the Colorado would be silted up as the Lower San Juan is being at present. The numerous half filled-up channels and long lagoons throughout the delta show the various courses the river has at different times taken.
Our boatmen paddled on until nine o'clock, when we anchored in the middle of the stream, which was here about one hundred yards wide. Distant as we were from the shore, we were not too far for the mosquitoes, which came off in myriads to the banquet upon our blood. Sleep for me was impossible, and to add to the discomfort, the rain came down in torrents. We had an old tarpaulin with us, but it was full of holes, and let in the water in little streams, so that I was soon soaked to the skin. Altogether, with the streaming wet and the mosquitoes, it was one of the most uncomfortable nights I have ever passed.
The waning moon was sufficiently high at four o'clock to allow us to bring the long dreary night to an end, and to commence paddling up the river again. As the day broke the rain ceased, the mists cleared away, our spirits revived, and we forgot our discomforts of the night in admiration of the beauties of the river. The banks were hidden by a curtain of creeping and twining plants, many of which bore beautiful flowers, and the green was further varied here and there by the white stems of the cecropia trees. Now and then we passed more open spots, affording glimpses into the forest, where grew, in the dark shade, slender-stemmed palms and beautiful tree-ferns, contrasting with the great leaves of the Heliconiae. At seven we breakfasted on a sand-bank, and got our clothes and blankets dried. There were numerous tracks of alligators, but it was too early to look for their eggs in the sand; a month later, in March, when the river falls, they are found in abundance, and eaten by the canoe-men. At noon we reached the point where the Seripiqui, a river coming down from the interior of Costa Rica, joins the San Juan about thirty miles above Greytown. The Seripiqui is navigable by canoes for about twenty miles from this point, and then commences a rough mountain mule-track to San Jose, the capital of Costa Rica. We paddled on all the afternoon with little change in the river. At eight we anchored for the night, and although it rained heavily again, I was better prepared for it, and, coiling myself up under an umbrella beneath the tarpaulin, managed to sleep a little.
We started again before daylight, and at ten stopped at a small clearing for breakfast. I strolled back a little way into the gloomy forest, but it was not easy to get along on account of the undergrowth and numerous climbing plants that bound it together. I saw one of the large olive-green and brown mot-mots (Momotus martii), sitting upon a branch of a tree, moving its long curious tail from side to side, until it was nearly at right angles to its body. I afterwards saw other species in the forests and savannahs of Chontales. They all have several characters in common, linked together in a series of gradations. One of these features is a spot of black feathers on the breast. In some species this is edged with blue, in others, as in the one mentioned above, these black feathers form only a small black spot nearly hidden amongst the rust-coloured feathers of the breast. Characters such as these, very conspicuous in some species, shading off in others through various gradations to insignificance, if not extinction, are known by naturalists to occur in numerous genera; and so far they have only been explained on the supposition of the descent of the different species from a common progenitor.
(PLATE 3. HEADS OF MOT-MOTS.)
As I returned to the boat, I crossed a column of the army or foraging ants, many of them dragging along the legs and mangled bodies of insects that they had captured in their foray. I afterwards often encountered these ants in the forests and it may be convenient to place together all the facts I learnt respecting them.
ECITONS, OR FORAGING ANTS.
The Ecitons, or foraging ants, are very numerous throughout Central America. Whilst the leaf-cutting ants are entirely vegetable feeders, the foraging ants are hunters, and live solely on insects or other prey; and it is a curious analogy that, like the hunting races of mankind, they have to change their hunting-grounds when one is exhausted, and move on to another. In Nicaragua they are generally called "Army Ants." One of the smaller species (Eciton predator) used occasionally to visit our house, swarm over the floors and walls, searching every cranny, and driving out the cockroaches and spiders, many of which were caught, pulled or bitten to pieces, and carried off. The individuals of this species are of various sizes; the smallest measuring one and a quarter lines, and the largest three lines, or a quarter of an inch.
I saw many large armies of this, or a closely allied species, in the forest. My attention was generally first called to them by the twittering of some small birds, belonging to several different species, that follow the ants in the woods. On approaching to ascertain the cause of this disturbance, a dense body of the ants, three or four yards wide, and so numerous as to blacken the ground, would be seen moving rapidly in one direction, examining every cranny, and underneath every fallen leaf. On the flanks, and in advance of the main body, smaller columns would be pushed out. These smaller columns would generally first flush the cockroaches, grasshoppers, and spiders. The pursued insects would rapidly make off, but many, in their confusion and terror, would bound right into the midst of the main body of ants. A grasshopper, finding itself in the midst of its enemies, would give vigorous leaps, with perhaps two or three of the ants clinging to its legs. Then it would stop a moment to rest, and that moment would be fatal, for the tiny foes would swarm over the prey, and after a few more ineffectual struggles it would succumb to its fate, and soon be bitten to pieces and carried off to the rear. The greatest catch of the ants was, however, when they got amongst some fallen brushwood. The cockroaches, spiders, and other insects, instead of running right away, would ascend the fallen branches and remain there, whilst the host of ants were occupying all the ground below. By and by up would come some of the ants, following every branch, and driving before them their prey to the ends of the small twigs, when nothing remained for them but to leap, and they would alight in the very throng of their foes, with the result of being certainly caught and pulled to pieces. Many of the spiders would escape by hanging suspended by a thread of silk from the branches, safe from the foes that swarmed both above and below.
I noticed that spiders were generally most intelligent in escaping, and did not, like the cockroaches and other insects, take shelter in the first hiding-place they found, only to be driven out again, or perhaps caught by the advancing army of ants. I have often seen large spiders making off many yards in advance, and apparently determined to put a good distance between themselves and their foe. I once saw one of the false spiders, or harvest-men (Phalangidae), standing in the midst of an army of ants, and with the greatest circumspection and coolness lifting, one after the other, its long legs, which supported its body above their reach. Sometimes as many as five out of its eight legs would be lifted at once, and whenever an ant approached one of those on which it stood, there was always a clear space within reach to put down another, so as to be able to hold up the threatened one out of danger.
I was much more surprised with the behaviour of a green, leaf-like locust. This insect stood immovably amongst a host of ants, many of which ran over its legs, without ever discovering there was food within their reach. So fixed was its instinctive knowledge that its safety depended on its immovability, that it allowed me to pick it up and replace it amongst the ants without making a single effort to escape. This species closely resembles a green leaf, and the other senses, which in the Ecitons appear to be more acute than that of sight, must have been completely deceived. It might easily have escaped from the ants by using its wings, but it would only have fallen into as great a danger, for the numerous birds that accompany the army ants are ever on the look out for any insect that may fly up, and the heavy flying locusts, grasshoppers, and cockroaches have no chance of escape. Several species of ant-thrushes always accompany the army ants in the forest. They do not, however, feed on the ants, but on the insects they disturb. Besides the ant-thrushes, trogons, creepers, and a variety of other birds, are often seen on the branches of trees above where an ant army is foraging below, pursuing and catching the insects that fly up.
The insects caught by the ants are dismembered, and their too bulky bodies bitten to pieces and carried off to the rear. Behind the army there are always small columns engaged on this duty. I have followed up these columns often; generally they led to dense masses of impenetrable brushwood, but twice they led me to cracks in the ground, down which the ants dragged their prey. These habitations are only temporary, for in a few days not an ant would be seen in the neighbourhood; all would have moved off to fresh hunting-grounds.
Another much larger species of foraging ant (Eciton hamata) hunts sometimes in dense armies, sometimes in columns, according to the prey it may be after. When in columns, I found that it was generally, if not always, in search of the nests of another ant (Hypoclinea sp.), which rear their young in holes in rotten trunks of fallen timber, and are very common in cleared places. The Ecitons hunt about in columns, which branch off in various directions. When a fallen log is reached, the column spreads out over it, searching through all the holes and cracks. The workers are of various sizes, and the smallest are here of use, for they squeeze themselves into the narrowest holes, and search out their prey in the furthest ramifications of the nests. When a nest of the Hypoclinea is attacked, the ants rush out, carrying the larvae and pupae in their jaws, only to be immediately despoiled of them by the Ecitons, which are running about in every direction with great swiftness. Whenever they come across a Hypoclinea carrying a larva or pupa, they capture the burden so quickly, that I could never ascertain exactly how it was done.
As soon as an Eciton gets hold of its prey, it rushes off back along the advancing column, which is composed of two sets, one hurrying forward, the other returning laden with their booty, but all and always in the greatest haste and apparent hurry. About the nest which they are harrying everything is confusion, Ecitons run here and there and everywhere in the greatest haste and disorder; but the result of all this apparent confusion is that scarcely a single Hypoclinea gets away with a pupa or larva. I never saw the Ecitons injure the Hypoclineas themselves, they were always contented with despoiling them of their young. The ant that is attacked is a very cowardly species, and never shows fight. I often found it running about sipping at the glands of leaves, or milking aphides, leaf-hoppers, or scale-insects that it found unattended by other ants. On the approach of another, though of a much smaller species, it would immediately run away. Probably this cowardly and un-antly deposition has caused it to become the prey of the Eciton. At any rate, I never saw the Ecitons attack the nest of other species.
The moving columns of Ecitons are composed almost entirely of workers of different sizes, but at intervals of two or three yards there are larger and lighter-coloured individuals that will often stop, and sometimes run a little backward, halting and touching some of the ants with their antennae. They look like officers giving orders and directing the march of the column.
This species is often met with in the forest, not in quest of one particular form of prey, but hunting, like Eciton predator, only spread out over a much greater space of ground. Crickets, grasshoppers, scorpions, centipedes, wood-lice, cockroaches, and spiders are driven out from below the fallen leaves and branches. Many of them are caught by the ants; others that get away are picked up by the numerous birds that accompany the ants, as vultures follow the armies of the East. The ants send off exploring parties up the trees, which hunt for nests of wasps, bees, and probably birds. If they find any, they soon communicate the intelligence to the army below, and a column is sent up immediately to take possession of the prize. I have seen them pulling out the larvae and pupae from the cells of a large wasp's nest, whilst the wasps hovered about, powerless, before the multitude of the invaders, to render any protection to their young.
I have no doubt that many birds have acquired instincts to combat or avoid the great danger to which their young are exposed by the attacks of these and other ants. Trogons, parrots, toucans, mot-mots, and many other birds build in holes of trees or in the ground, and these, with their heads ever turned to the only entrance, are in the best possible position to pick off singly the scouts when they approach, thus effectually preventing them from carrying to the main army intelligence about the nest. Some of these birds, and especially the toucans, have bills beautifully adapted for picking up the ants before they reach the nest. Many of the smaller birds build on the branches of the bull's-horn thorn, which is always thickly covered with small stinging honey-eating ants, that would not allow the Ecitons to ascend these trees.
Amongst the mammalia the opossums can convey their young out of danger in their pouches, and the females of many of the tree-rats and mice have a hard callosity near the teats, to which the young cling with their milk teeth, and can be dragged away by the mother to a place of safety.
The eyes in the Ecitons are very small, in some of the species imperfect, and in others entirely absent; in this they differ greatly from those ants which hunt singly, and which have the eyes greatly developed. The imperfection of eyesight in the Ecitons is an advantage to the community, and to their particular mode of hunting. It keeps them together, and prevents individual ants from starting off alone after objects that, if their eyesight were better, they might discover at a distance. The Ecitons and most other ants follow each other by scent, and, I believe, they can communicate the presence of danger, of booty, or other intelligence, to a distance by the different intensity or qualities of the odours given off. I one day saw a column of Eciton hamata running along the foot of a nearly perpendicular tramway cutting, the side of which was about six feet high. At one point I noticed a sort of assembly of about a dozen individuals that appeared in consultation. Suddenly one ant left the conclave, and ran with great speed up the perpendicular face of the cutting without stopping. It was followed by others, which, however, did not keep straight on like the first, but ran a short way, then returned, then again followed a little further than the first time. They were evidently scenting the trail of the pioneer, and making it permanently recognisable. These ants followed the exact line taken by the first one, although it was far out of sight. Wherever it had made a slight detour they did so likewise. I scraped with my knife a small portion of the clay on the trail, and the ants were completely at fault for a time which way to go. Those ascending and those descending stopped at the scraped portion, and made short circuits until they hit the scented trail again, when all their hesitation vanished, and they ran up and down it with the greatest confidence. On gaining the top of the cutting, the ants entered some brushwood suitable for hunting. In a very short space of time the information was communicated to the ants below, and a dense column rushed up to search for their prey.
The Ecitons are singular amongst the ants in this respect, that they have no fixed habitations, but move on from one place to another, as they exhaust the hunting grounds around them. I think Eciton hamata does not stay more than four or five days in one place. I have sometimes come across the migratory columns. They may easily be known by all the common workers moving in one direction, many of them carrying the larvae and pupae carefully in their jaws. Here and there one of the light-coloured officers moves backwards and forwards directing the columns. Such a column is of enormous length, and contains many thousands, if not millions of individuals. I have sometimes followed them up for two or three hundred yards without getting to the end.
They make their temporary habitations in hollow trees, and sometimes underneath large fallen trunks that offer suitable hollows. A nest that I came across in the latter situation was open at one side. The ants were clustered together in a dense mass, like a great swarm of bees, hanging from the roof, but reaching to the ground below. Their innumerable long legs looked like brown threads binding together the mass, which must have been at least a cubic yard in bulk, and contained hundreds of thousands of individuals, although many columns were outside, some bringing in the pupae of ants, others the legs and dissected bodies of various insects. I was surprised to see in this living nest tubular passages leading down to the centre of the mass, kept open just as if it had been formed of inorganic materials. Down these holes the ants who were bringing in booty passed with their prey. I thrust a long stick down to the centre of the cluster, and brought out clinging to it many ants holding larvae and pupae, which probably were kept warm by the crowding together of the ants. Besides the common dark-coloured workers and light-coloured officers, I saw here many still larger individuals with enormous jaws. These they go about holding wide open in a threatening manner, and I found, contrary to my expectation, that they could give a severe bite with them, and that it was difficult to withdraw the jaws from the skin again.
One day when watching a small column of these ants, I placed a little stone on one of the ants to secure it. The next that approached, as soon as it discovered the situation of the prisoner, ran backwards in an agitated manner, and communicated the intelligence to the others. They rushed to the rescue, some bit at the stone and tried to move it, others seized the captive by the legs, and tugged with such force that I thought the legs would be pulled off, but they persevered until they freed it. I next covered one up with a piece of clay, leaving only the ends of its antennae projecting. It was soon discovered by its fellows, which set to work immediately, and by biting off pieces of the clay, soon liberated it. Another time I found a very few of them passing along at intervals. I confined one of these under a piece of clay, at a little distance from the line, with his head projecting. Several ants passed it, but at last one discovered it and tried to pull it out, but could not. It immediately set off at a great rate, and I thought it had deserted its comrade, but it had only gone for assistance, for in a short time about a dozen ants came hurrying up, evidently fully informed of the circumstances of the case, for they made directly for their imprisoned comrade, and soon set him free. I do not see how this action could be instinctive. It was sympathetic help, such as man only among the higher mammalia shows. The excitement and ardour with which they carried on their unflagging exertions for the rescue of their comrade could not have been greater if they had been human beings, and this to meet a danger that can be only of the rarest occurrence. Amongst the ants of Central America I place the Eciton as the first in intelligence, and as such at the head of the Articulata. Wasps and bees come next to ants, and then others of the Hymenoptera. Between ants and the lower forms of insects there is a greater difference in reasoning powers than there is between man and the lowest mammalian. A recent writer has argued that of all animals ants approach nearest to man in their social condition.* (*Houzeau, "Etudes sur les Facultes mentales des Animaux comparees a celles de l'Homme.") Perhaps if we could learn their wonderful language we should find that even in their mental condition they also rank next to humanity.
I shall relate two more instances of the use of a reasoning faculty in these ants. I once saw a wide column trying to pass along a crumbling, nearly perpendicular, slope. They would have got very slowly over it, and many of them would have fallen, but a number having secured their hold, and reaching to each other, remained stationary, and over them the main column passed. Another time they were crossing a water-course along a small branch, not thicker than a goose-quill. They widened this natural bridge to three times its width by a number of ants clinging to it and to each other on each side, over which the column passed three or four deep. Except for this expedient they would have had to pass over in single file, and treble the time would have been consumed. Can it not be contended that such insects are able to determine by reasoning powers which is the best way of doing a thing, and that their actions are guided by thought and reflection? This view is much strengthened by the fact that the cerebral ganglia in ants are more developed than in any other insect, and that in all the Hymenoptera, at the head of which they stand, "they are many times larger than in the less intelligent orders, such as beetles."* (* Darwin, "Descent of Man" volume 1 page 145.) |
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