Mutual Aid: A Factor of Evolution

However, it is especially with the rodents, the un- gulata, and the ruminants that we find a highly- developed practice of mutual aid. The squirrels are individualist to a great extent. Each of them builds its own comfortable nest, and accumulates its own provision. Their inclinations are towards family life, and Brehm found that a family of squirrels is never so happy as when the two broods of the same year can join together with their parents in a remote corner of a forest. And yet they maintain social relations. The inhabitants of the separate nests remain in a close intercourse, and when the pine-cones become rare in the forest they inhabit, they emigrate in bands. As to the black squirrels of the Far West, they are eminently sociable. Apart from the few hours given every day to foraging, they spend their lives in playing in numerous parties. And when they multiply too rapidly in a region, they assemble in bands, almost as numerous as those of locusts, and move southwards, devastating the forests, the fields, and the gardens ; while foxes, polecats, falcons, and nocturnal birds of prey follow their thick columns and live upon the individuals remaining behind. The ground-squirrel — a closely-akin genus — is still more sociable. It is given to hoarding, and stores up in its subterranean

halls large amounts of edible roots and nuts, usually plundered by man in the autumn. According to some observers, it must know something of the joys of a miser. And yet it remains sociable. It always lives in large villages, and Audubon, who opened some dwellings of the hackee in the winter, found several individuals in the same apartment ; they must have stored it with common efforts. The large tribe of the marmots, which includes the three large genuses of Arctomys, Cynomys, and Sper- mopkilus, is still more sociable and still more intelligent. They also prefer having each one its own dwelling ; but they live in big villages. That terrible enemy of the crops of South Russia — the souslik — of which some ten millions are exterminated every year by man eJone, lives in numberless colonies ; and while the Russian provincial assemblies gravely discuss the means of getting rid of this enemy of society, it enjoys life in its thousands in the most joyful way. Their play is so charming that no observer could refrain from paying them a tribute of praise, and from mention- ing the melodious concerts arising from the sharp whistlings of the males and the melancholic whistlings of the females, before — suddenly returning to his citizen's duties — he begins inventing the most diabolic means for the extermination of the little robbers. All kinds of rapacious birds and beasts of prey having proved powerless, the last word of science in this warfare is the inoculation of cholera ! The villages of the prairie-dogs in America are one of the loveliest sights. As far as the eye can embrace the prairie, it sees heaps of earth, and on each of them a prairie-dog stands, engaged in a lively conversation with its neighbours by means of short barkings. As soon as

the approach of man is signalled, all plunge in a moment into their dwellings ; all have disappeared as by enchantment. But if the danger is over, the little creatures soon reappear. Whole families come out of their galleries and indulge in play. The young ones scratch one another, they worry one another, and display their gracefulness while standing upright, and in the meantime the old ones keep watch. They go visiting one another, and the beaten footpaths which connect all their heaps testify to the frequency of the visitations. In short, the best naturalists have written some of their best pages in describing the associations of the prairie-dogs of America, the marmots of the Old World, and the polar marmots of the Alpine regions. And yet, I must make, as regards the marmots, the same remark as I have made when speaking of the bees. They have maintained their fighting instincts, and these instincts reappear in captivity. But in their big associations, in the face of free Nature, the un- sociable instincts have no opportunity to develop, and the general result is peace and harmony. f Even such harsh animals as the rats, which con- I tinually fight in our cellars, are sufficiently intelligent J not to quarrel when they plunder our larders, but to aid one another in their plundering expeditions and migrations, and even to feed their invalids. As to the "^ beaver-rats or musk-rats of Canada, they are extremely sociable. Audubon could not'but admire " their peace- ful communities, which require only being left in peace to enjoy happiness." Like all sociable animals, they are lively and playful, ■ they easily combine with other species, and they have attained a very high degree of intellectual development. In their villages, always disposed on the shores of lakes and rivers, they take

into account the changing level of water ; their dome- shaped houses, which are built of beaten clay inter- woven with reeds, have separate corners for organic refuse, and their halls are well carpeted at winter- time ; they are warm, and, nevertheless, well ventilated. As to the beavers, which are endowed, as known, with a most sympathetic character, their astounding dams and villages, in which generations live and die without knowing of any enemies but the otter and man, so wonderfully illustrate what mutual aid can achieve for the security of the species, the develop- ment of social habits, and the evolution of intelligence, that they ar^ familiar to all interested in animal life. Let me only remark that with the beavers, the musk- rats, and some other rodents, we already find the feature which will also be distinctive of human com- munities— that is, work in common.

I pass in silence the two large families which include the jerboa, the chinchilla, the biscacha, and the tushkan, or underground hare of South Russia, though all these small rodents might be taken as excellent illustrations of the pleasures derived by animals from' social life.^ Precisely, the pleasures ; because it is extremely diffi- cult to say what brings animals together — the needs of mutual protection, or simply the pleasure of feeling surrounded by their congeners. At any rate, our common hares, which do not gather in societies for life

1 With regard to the viscacha it is very interesting to note that these highly-sociable little animals not only live peaceably together in each village, but that whole villages visit each other at nights. Sociability is thus extended to the whole species — not only to a given society, or to a nation, as we saw it with the ants. When the farmer destroys a viscacha-burrow, and buriea the inhabitants under a heap of earth, other viscachas — ^we are told by Hudson— "come from a distance to dig out those that are buried alive" (I.e., p. 311). This is a widely-known fact in La Plata, verified by the author.

in common, and which are not even endowed with intense parental feelings, cannot live without coming together for play. Dietrich de Winckell, who is considered to be among the best acquainted with the habits of hares, describes them as passionate players, becoming so intoxicated by their play that a hare has been known to take an approaching fox for a playmate.^ As to the rabbit, it lives in societies, and its family life is entirely built upon the image of the old patri- archal family ; the young ones being kept in absolute obedience to the father and even the grandfather. ^ And here we have the example of two very closely- allied species which cannot bear each other — not because they live upon nearly the same food, as like cases are too often explained, but most probably because the passionate, eminently-individualist hare cannot make friends with that placid, quiet, and sub- missive creature, the rabbit. Their tampers are too widely different not to be an obstacle to friendship.

Life in societies is again the rule with the large family of horses, which includes the wild horses and donkeys of Asia, the zebras, the mustangs, the cimar- rones of the Pampas, and^ the half-wild horses of Mongolia and Siberia^ythey all live in numerous associations made up of many studs, each of which consists of a number of mares under the leadership of a male. These numberless inhabitants of the Old and the New World, badly organized on the whole for resisting both their numerous enemies and the adverse conditions of climate, would soon have disappeared

1 Handbuch filr Jdger und Jagdberechtigie, quoted by Brehm, ii. from the surface of the earth were it not for their sociable spirit. When a beast of prey approaches them, several sfuds unite at once ; they repulse the beast and sometimes chase it : and neither the wolf nor the bear, not even the lion, can capture a horse or even a zebra as long as they are not detached from the herd. When a drought is burning the grass in the prairies, they gather in herds of sometimes 10,000 individuals strong, and migrate. And when a snow- storm rages in the Steppes, each stud keeps close together, and repairs to a protected ravine. But if confidence disappears, or the group has been seized by panic, and disperses, the horses perish and the survivors are found after the storm half dying from fatigue. Union is their chief arm in the struggle for life, and man is their chief enemy. Before his increas- ing numbers the ancestors of our domestic horse (the Eqtius Przewalskii, so named by Polyakoff) have pre- ferred to retire to the wildest and least accessible plateaus on the outskirts of Thibet,, where they con- tinue to live, surrounded by carnivores, under a climate as bad as that of the Arctic regions, but in a region inaccessible to man.'^

Many striking illustrations of social life could be taken from the life of the reindeer, and especially of ^ In connection with the horses it is worthy of notice that the quagga zebra, which never comes together with the dauw zebra, nevertheless lives on excellent terms, not only with ostriches, which are very good sentries, but also with gazelles, several species of antelopes, and gnus. We thus have a case of mutual disUke between the quagga and the dauw which cannot be explained by competition for food. The fact that the quagga lives together with ruminants feeding on the same grass as itself excludes that hjrpothesis, and we must look for some incompatibility of character, as in the case of the hajre and the rabbit. Cf., among others, Clive Phillips-Wolley's Big Game Shooting (Badminton Library), which contains excellent illustrations of various species living together in East Africa.

that large division of ruminants which might include the roebucks, the fallow deer, the antelopes, the gazelles, the ibex, and, in fact, the whole of the three numerous families of the Antelopides, the Caprides, and the Ovides. Their watchfulness over the safety of their herds against attacks of carnivores ; the anxiety displayed by all individuals in a 'herd of chamois as long as all of them have not cleared a difficult passage over rocky cliffs ; the adoption of orphans ; the despair of the gazelle whose mate, or even comrade of the same sex, has been killed ; the plays of the youngsters, and many other features, could be mentioned. But perhaps the most striking illustration of mutual support is given by the occa- sional migrations of fallow deer, such as I saw once on the Amur. When I crossed the high plateau and its border ridge, the Great Khingan, on my way from Transbaikalia to Merghen, and further travelled over the high prairies on my way to the Amur, I could ascertain how thinly-peopled with fallow deer these mostly uninhabited regions are.^ Two years later I was travelling up the Amur, and by the end of October reached the lower end of that picturesque gorge which the Amur pierces in the Dousse-alin (Little Khingan) before it enters the lowlands where it joins the Sungari. I found the Cossacks in the villages of that gorge in the greatest excitement, because thousands and thousands of fallow deer were crossing the Amur where it is narrowest, in order to reach the lowlands. For several days in succession,

1 Our Tungus hunter, who was going to marry, and therefore was prompted by the desire of getting as many furs as he possibly could, was beating the hill-sides all day long on horseback in search of deer. His efforts were not rewarded by even so much as one fallow deer killed every day ; and he was an excellent hunter. upon a length of some forty miles up the river, the Cossacks were butchering the deer as they crossed the Amur, in which already floated a good deal of ice. Thousands were killed every day, and the exodus nevertheless continued. Like migrations were never seen either before or since, and this one must have been called for by an early and heavy snow-fall in the Great Khingan, which compelled the deer to make a desperate attempt at reaching the lowlands in the east of the Dousse mountains. Indeed, a few days later the Dousse-alin was also buried under snow two or three feet deep. Now, when one imagines the immense territory (almost as big as Great Britain) from which the scattered groups of deer must have gathered for a migration which was undertaken under the pressure of exceptional circumstances, and realizes the difficulties which had to be overcome before all the deer came to the common idea of crossing the Amur further south, where it is narrowest, one cannot but deeply admire the amount of sociability displayed by these intelligent animals. The fact is not the less striking if we remember that the buffaloes of North America displayed the same powers of combination. One saw them grazing in great numbers in the plains, but these numbers were made up by an infinity of small groups which never mixed together. And yet, when necessity arose, all groups, however scattered over an immense territory, came together and made up those immense columns, numbering hundreds of thousands of individuals, which I mentioned on a preceding page.

I also ought to say a few words at least about the " compound families " of the elephants, their mutual attachment, their deliberate ways in posting sentries, and the feelings of sympathy developed by such a life of close mutual support.^ I might mention the soci- able feelings of those disreputable creatures the wild boars, and find a word of praise for their powers of association in the case of an attack by a beast of prey.^ The hippopotamus and the rhinoceros, too, would occupy a place in a work devoted to animal sociability.^ Several striking pages might be given to the socT- ability and mutual attachment of the seals and the walruses ; and finally, one might mention the most excellent feelings existing among the sociable ceta- ceans. But I have to say yet a few words about the societies of monkeys, which acquire an additional interest from their being the link which will bring us to the societies of primitive men.

It is hardly needful to say that those mammals, which stand at the very top of the animal world and most approach man by their structure and intelligence, are eminently sociable. Evidently we must be pre- pared to meet with all varieties of character and habits in so great a division of the animal kingdom which includes hundreds of species. But, all things con- sidered, it must be said that sociability, action in common, mutual protection, and a high development of those feelings which are the necessary outcome of social life, are characteristic of most monkeys and_ ..ages. From the smallest species to the biggest ones, sociability is a rule to which we know but a few

1 According to Samuel W. Baker, elephants combine in larger groups than the "compound family." "I have ' frequently observed," he wrote, " in the portion of Ceylon known as the Park Country, the tracks of elephants in great numbers which have evidently been considerable herds that have joined together in a general retreat from a ground which they considered insecure " \Wild Beasts and their Ways, vol. i. p. 102). exceptions. The nocturnal apes prefer isolated life ; the capuchins {Cebus capucinus), the monos, and the howling monkeys live but in small families ; and the orang-outans have never been seen by A. R. Wallace otherwise than either solitary or in very small groups of three or four individuals, while the gorillas seem never to join in bands. But all the remainder of the monkey tribe — the chimpanzees, the sajous, the sakis, the mandrills, the baboons, and so on — are sociable in the highest degree. They live in great bands, and even join with other species than their own. Mpst of them become q^uite unhappy when solitary. The cries of distress of each one of the band immediately" bring together the"wE6le'6f "the band, and they boTdly repulse the attacks oT most~"cafffi'vof es a"nd~birds~af" prey. ETven eagIes~do not dare attack thpm. They plunder our fields always in bands — the old ones taking care for the safety of the commonwealth. The little tee-tees, whQse childish sweet faces so much struck Humboldt, erribrace and, protect one another when it rains, rolling their tails over the jiecks of their shivering comrades. Several species display tKe greatest solicitude for their wounded, and do not abandon a wounded comrade during a retreat till they have ascertained that it is dead and that they are help- less to restore it to life. Thus James Forbes narrated in his Oriental Memoirs a fact of such resistance in reclaiming from his hunting party the dead body of a female monkey that one fully understands why " the witnesses of this extraordinary scene resolved never again to fire at one of the monkey race." ^ In some species several individuals will combine to overturn a stone in order to search for ants' eggs under it. The 1 ^0X03X10,%' z Animal Intelligence, 1^. 472.

hamadryas not only post sentries, but have been seen making a chain for the transmission of the spoil to a safe place ; and their courage is well known. Brehm's description of the regular fight which his caravan had to sustain before the hamadryas would let it resume its journey in the valley of the Mensa, in Abyssinia, has become classical.^ The playfulness of the tailed apes and the mutual attachment which reigns in the families of chimpanzees also are familiar to the general reader. And if we find among the highest apes two species, the orang-outan and the gorilla, which are not sociable, we must remember that both — limited as they are to very small areas, the one in the heart of Africa, and the other in the two islands of Borneo and Sumatra — have all the appearance of being the last remnants of formerly much more numerous species. The gorilla at least seems to have been sociable in olden times, if the apes mentioned in the Periplus really were gorillas. .

We thus see, even from the above brief review, that life in societies is no exception in the animal world; it is the rule, the law of Nature, and it reaches its fullest development with the higher vertebrates. Those species which live solitary, or in small families only, are relatively few, and their numbers are limited. Nay, it appears very probable that, apart from a few ^exceptions' those birds and mammals which are not gregarious now, were living in societies before man mintip^eg"onTEe~earth and waged a permanent war against them, or destroyed the sources from which

1 Brehm, i. 82 ; Darwin's Descent of Man, ch. iii. The Kozloff expedition of 1 899-1 901 have also had to sustain in Northern Thibet a similar fight. they formerly derived food. "On ne s'associe pas pour mourir," was the sound remark of Espinas ; and Houzeau, who knew the animal world of some parts of America when it was not yet affected by man, wrote to the same effect. Association is found in the animal world at all degrees of evolution ; and, according to the grand idea of Herbert Spencer, so brilliantly developed in Perrier's Colonies Animales, colonies are at the v.ery origin of evolution in the animal kingdom. But, in A proportion as we ascend the scale of evolution, we see If association growing more and more conscious. It ) loses its purely physical character, it ceases to be/i simply instinctive, it becomes reasoned. With the// higher vertebrates it is periodical, or is resorted to for { the satisfaction of a given want — propagation of the j species, migration, hunting, or mutual defencerr^lt even becomes occasional, when birds associate against a robber, or mammals combine, under the pressure of exceptional circumstances, to emigrate. In this last case, it becomes a voluntary deviation from habitual moods of life. The combination sometimes appears in two or more degrees — the family first, then the group, and finally the association of groups, habitually scattered, but uniting in case of need, as we saw it with the bisons and other ruminants. It also takes higher forms, guaranteeing more independence to the individual without depriving it of the benefits of social life. With most rodents the individual has its own dwelling, which it can retire to when it prefers being left alone ; but the dwellings are laid out in ; villages and cities, so as to guarantee to all inhabitants the benefits and joys of social life. And finally, in several species, such as rats, marmots, hares, etc.,

sociable life is maintained notwithstanding the quarrel- some or otherwise egotistic inclinations of the isolated individual. Thus it is not imposed, as is the case with ants and bees, by the very physiological structure of the individuals; it is cultivated for the benefits of mutual aid, or for the sake of its pleasures. And this, of course, appears with all possible gradations and with the greatest variety of individual and specific characters — the very variety of aspects taken by social life being a consequence, and for us a further proof, of its generality.^

Sociability — that is, the need of the animal of associating with its like — the love of society for society's sake, combined with the "joy of life," only now begins to receive due attention from the zoologists.^ We know at the present time that all animals, beginning - with the ants, going on to the birds, and ending with the highest mammals, are fond of plays, wrestling, running after each other, trying to capture each other, teasing each other, and so on. And while many plays are, so to speak, a school for the proper behaviour of the young in mature life, there are others, which, apart from their utilitarian purposes, are, together with dancing and singing, mere manifestations of an excess of forces — " the joy of life," and a desire to communi- cate in some way or another with other individuals of

1 The more strange was it to read in the previously-mentioned article by Huxley the following paraphrase of a well-known sentence of Rousseau : " The first men who substituted mutual peace for that of mutual war — whatever the motive which impelled them to take that step — created society" {Nineteenth Century, Feb. 1888, p. 165). Society has not been created by man ; it is anterior to man. 2 Such monographs as the chapter on " Music and Dancing in Nature " which we have in Hudson's Naturalist on the La Plata, and Carl Gross' Play of Animals, have already thrown a considerable light upon an instinct which is absolutely universal in Nature.

the same or of other species — in short, a manifestation of sociability proper, which is a distinctive feature of all the animal world.^ Whether the feeling be fear, experienced at the appearance of a bird of prey, or " a fit of gladness " which bursts out when the animals are in good health and especially when young, or merely the desire of giving play to an excess of impressions and of vital power— the necessity of communicating impressions, of playing, of chattering, or of simply feeling the proximity of other kindred living beings pervades Nature, and is, as much as any other physio- logical function, a distinctive feature of life and impres- sionabihty. This need takes a higher development and attains a more beautiful expression in mammals, especially amidst their young, and still more among the birds ; but it pervades all Nature, and has been fully observed by the best naturalists, including Pierre Huber, even amongst the ants, and it is evidently the same instinct which brings together the big columns of butterflies which have been referred to already.

The habit of coming together for dancing and of decorating the places where the birds habitually perform their dances is, of course, well known from the pages that Darwin gave to this subject in The Descent of Man (ch. xiii.). Visitors of the London Zoological Gardens also know the bower of the satin bower-bird. But this habit of dancing seems to be much more widely spread than was formerly believed, and Mr, W. 1 Not only numerous species of birds possess the habit of assembling together — in many cases always at the same spot — to indulge in antics and dancing performances, but W. H. Hudson's experience is that nearly all mammals and birds (" probably there are really no exceptions ") indulge frequently in more or less regular or set performances with or without sound, or composed of sound exclusively (p. 264).

Hudson gives in his master-work on La Plata the most interesting description, which must be read in the original, of complicated dances, performed by quite a number of birds : rails, jacanas, lapwings, and so on. The habit of singing in concert, which exists in several species of birds, belongs to the same category of social instincts. It is most strikingly developed with the chakar {Chauna chavarria), to which the English have given the most unimaginative misnomer of "crested screamer." These birds sometimes assemble in immense flocks, and in such cases they frequently sing all in concert. W. H. Hudson found them once in countless numbers, ranged all round a pampas lake in well-defined flocks, of about 500 birds in each flock.

" Presently," he writes, " one flock near me began singing, and continued their powerful chant for three or four minutes ; when they ceased the next flock took up the strains, and after it the next, and so on, until once more the notes of the flocks on the opposite shore came floating strong and clear across the water — then passed away, growing fainter and fainter, until once more the sound approached me travelling round to my side again." j On another occasion the same writer saw a whole plain covered with an endless flock of chakars, not in close order, but scattered in pairs and small groups. About nine o'clock in the evening, " suddenly the entire multitude of birds covering the marsh for miles around burst forth in a tremendous evening song. . . . It was a concert well worth riding a hundred miles to hear." ^ It may be added that like all sociable animals, the chakar easily becomes tame and grows very attached to man. " ThgY^are mild-temperedJakda. and

very rarely quarrel " — we aj::£-iald..i.akhougcli--th£y--aj:e well prnviflprl with formidable weapons. Life in __societies renders these weapons useless. That life in societies is the most powerful weapon in the struggle for life, taken in its widest sense, has been illustrated by several examples on the foregoing pages, and could be illustrated by any amount of evidence, if further evidence were required. Life in societies enables the feeblest insects, the feeblest birds, and the feeblest mammals to resist, or to protect themselves from, the most terrible birds and beasts of prey ; it permits longevity ; it enables the species to rear its progeny with the least waste of energy and to maintain its numbers albeit a very slow birth-rate ; it enables the gregarious animals to migrate in search of new abodes. Therefore, while fully admitting that force, swiftness, protective colours, cunningness, and endur- ance to hunger and cold, which are mentioned by Darwin and Wallace, are so many qualities making the individual, or the species, the fittest under certain circumstances, we maintain that under any circum- stances fi"'^ia^-"'Vity is th-^ grp^i-pgt arlv;)f|t:age in the struggle fnr )ifp. TVinc;p species which_willingly or unwillingly ah^nrlnn I'Tare doomed to _decav: ; while those animals which know best how to combine, have the greatest chances of survival and of further^evolu- tion, although they may be inferior to others, in each of the faculties enumerated by Darwin and Wallace, save the intellectual faculty. The highest vertebrates, and especially mankind, are the best proof of this assertion. As to the intellectual faculty, while every Darwinist will agree with Darwin that it is the most powerful arm in the struggle for life, and the most

powerful factor of further evolution, he also will admit that intelligence is an eminently social faculty. Language, imitation, and accumulated experience are so many elements of growing intelligence of which the unsociable animal is deprived. Therefore we find, at the top of each class of animals, the ants, the parrots, and the monkeys, all combining the greatest sociability with the highest development of intelligence. The fittest are thus the most sociable animals, and soci- ability appears as the chief factor of evolution, both directly, by securing the well-being of the species while diminishing the waste of energy, and indirectly, by favouring the growth of intelligence.

Moreover, it is evident that life in societies would be utterly impossible without a corresponding develop- ment of social feelings, and, especially, of a certain collective sense of justice growing to become a habit. If every individual were constantly abusing its personal advantages without the others interfering in favour of the wronged, no society-life would be possible. And feelings of justice develop, more or less, with all gregarious animals. Whatever the distance from which the swallows or the cranes come, each one returns to the nest it has built or repaired last year. If a lazy sparrow intends appropriating the nest which a comrade is building, or even steals from it a few sprays of straw, the group interferes against the lazy comrade ; and it is evident that without such inter- ference being the rule, no nesting associations of birds could exist. Separate groups of penguins have separate resting-places and separate fishing abodes, and do not fight for them. The droves of cattle in Australia have particular spots to which each group repairs to rest, and from which it never deviates ; and

so on.^ We have any numbers of direct observations of the peace that prevails in the nesting associations of birds, the villages of the rodents, and the herds of grass-eaters ; while, on the other side, we know of few sociable animals which so continually quarrel as the rats in our cellars do, or as the morses, which fight for the possession of a sunny place on the shore. Sociability thus puts a limit to physical struggle, and leaves room for the development of better moral feel- ings. The high development of parental love in all classes of animals, even with lions and tigers, is generally known. As to the young birds and mam- mals whom we continually see associating, sympathy — not love — attains a further development in their associations. Leaving aside the really touching facts of mutual attachment and compassion which have been recorded as regards domesticated animals and with animals kept in captivity, we have a number of well- certified facts of compassion between wild animals at liberty. Max Perty and L. Buchner have given a number of such facts.^ J. C. Wood's narrative of a weasel which came to pick up and to carry away an injured comrade enjoys a well-merited popularity.^ So also the observation of Captain Stansbury on his journey to Utah which is quoted by Darwin ; he saw a blind pelican which was fed, and well fed, by other pelicans upon fishes which had to be brought from

- To quote but a few instances, a wounded badger was carried away by another badger suddenly appearing on the scene ; rats have been seen feeding a blind couple {Seelenleben der Thiere, p. 64 seq.). Brehm himself saw two crows feeding in a hollow tree a third crow which was wounded ; its wound was several weeks old {Hausfreund, 1874, 715; Biichner's Liebe, 203). Mr. Blyth saw Indian crows feeding two or three blind comrades ; and so on. a distance of thirty miles. ^ And when a herd of vicunas was hotly pursued by hunters, H. A. Weddell saw more than once during his journey to Bolivia and Peru, the strong males covering the retreat of the herd and lagging behind in order to protect the retreat. As to facts of compassion with wounded comrades, they are continually mentioned by all field zoologists. Such facts are quite natural. Compassion is a neces- sary outcome of social life. But compassion also means a considerable advance in general Intelligence and sensibility. It is the first step towards the development of higher moral sentiments. It is, in its turn, a powerful factor of further evolution.