Mutual Aid: A Factor of Evolution

both the animal world and ^nan societies. Only after this has been fully recognized wHnTbe possible to proceed to a comparison between the two factors. To make even a rough estimate of their relative importance by any method more or less statistical, is evidently impossible. One single war — we all know — may be productive of more evil, immediate and subsequent, than hundreds of years of the unchecked action of the mutual-aid principle may be productive of good. But when we see that in the animal world, progressive development and mutual aid go hand in hand, while the inner struggle within the species is concomitant with retrogressive development ; when we notice that with man, even success in struggle and war is proportionate to the development of mutual aid in each of the two conflicting nations, cities, parties, or tribes, and that in the process of evolution war itself (so far as it can go this way) has been made subservient to the ends of progress in mutual aid within the nation, the city or the clan— fwe already obtain a perception of the dominating influence of the mutual-aid factor as an element of progress?/ But we see also that the practice \o( mutual aid and its successive developments have ) created the very conditions of society life in which man i was enabled to develop his arts, knowledge, and /intelligence; and that the periods when institutions VhaspdmTfhpjTinfiial-aid tpndpnry tQpk their greatest development were ajso^ the periods of the greatest prog;ress_in arts, industry, and srienre. In fact, the study of the inner life of the mediaeval city and of the ancient Greek cities reveals the fact that the combina- tion of mutual aid, as it was practised within the guild

and the Greek clan, with a large initiative which was left to the individual and the group by means of the federative principle, gave to mankind the two greatest periods of its history — the ancient Greek city and the mediaeval city periods ; while the ruin of the above institutions during the State periods of history, which followed, corresponded in both cases to a rapid decay. As to the sudden industrial progress which has been achieved during our own century, and which is usually ascribedp to the triumph of individualism and compe- tition, it certainly has a much deeper origin than that. Once the great discoveries of the fifteenth century were made, especially that of the pressure of the atmosphere, supported by a series of advances in natural philosophy — and they were made under the mediaeval city organization, — once these discoveries were made, the invention of the steam-motor, and all the revolution which the conquest of a new power implied, had necessarily to follow. If the mediaeval cities had lived to bring their discoveries to that point, the ethical consequences of the revolution effected by steam might have been different ; but the same revolu- tion in technics and science would have inevitably taken place. It remains, indeed, an open question whether the general decay of industries which followed the ruin of the free cities, and was especially noticeable in the first part of the eighteenth century, did not con- siderably retard the appearance of the steam-engine as well as the consequent revolution in arts. When we consider the astounding rapidity of industrial progress from the twelfth to the fifteenth centuries — in weaving, working of metals, architecture and navigation, and ponder over the scientific discoveries which that indus- trial progress led to at the end of the fifteenth century —

we must ask ourselves whether mankind was not delayed in its taking full advantage of these conquests when a general depression of arts and industries took place in Europe after the decay of mediaeval civilization. Surely it was not the disappearance of the artist^ artisan, nor the ruin of large cities and the extinction of intercourse between them, which could favour the industrial revolution ; and we know indeed that James Watt spent twenty or more years of his life in order to render his invention serviceable, because he ^uld not find in the last century what he would have readily found in mediaeval Florence or Brugge, that is, the artisans capable of realizing his devices in metal, and of giving them the artistic finish and precision which the steam-engine requires.

To attribute, therefore, the industrial progress of our century to theju/^ar of each against all which it has proclaimed, is to reason like the man who, knowing not the causes of rain, attributes it to the victim he ' has immolated before his clay idol. For industrial progress, as for each other conquest over nature, i mutual aid and close intercourse certainly are, as they have been, much more advantageous than mutual struggle. • However, it is especially in the domain of ethics that the dominating importance of the mutual-aid principle appears in full. That mutual aid is the real foundation of our ethical conceptions seems evident (enough. But whatever the opinions as to the first

^ whether a biological or a supernatural cause is ascribed to it — we must trace its existence as far back as to the lowest stages of the animal world ; and from these stages we can follow its uninterrupted evolution, in opposition to a number of contrary agencies, through all degrees of human development, up to the present times. Even the new religions which were born from time to time — always at epochs when the mutual-aid s principle was falling into decay in the theocracies and despotic States of the East, or at the decline of the Roman Empire — even the new religions have only reaffirmed that same principle. They found their first supporter^ among the humble, in the lowest^ ^own- trnddf n l^^lllf i50r'f'''yjgdlgie.'^hp mutual-aid principle _^ is the necessary foundation of_ every-day life ; and thei' new forms of union which were introduced in the earliest Buddhist and Christian communities, in the Moravian brotherhoods and so on, took the character of a return to the best aspects of mutual aid in early tribal life.

Each time, however, that an attempt to return to this old principle was made, its fundamental idea itself 1 was widened. From the clan it was extended to the stem, to the federation of stems, to the nation, and finally — in ideal, at least — to the whole of mankind. It was also refined at the same time. In primitive Buddhism, in primitive Christianity, in the writings of some of the Mussulman teachers, in the early move- ments of the Reform, and especially in the ethical and philosophical movements of the last century and of our own times, the total abandonment of the idea of revenge, or of "due reward " — of good for good and evil for evil — is affirmed more and more vigorously. "" {The higher conception of "no revenge for wrongs," ^ and of freely giving more than one expects to receive , from his neighbours, is proclaimed as being the real ^ principle of morality — a principle superior to mere equivalence, equity, or justice, and more conducive to ^

happiness. And man is appealed to to be guided in his acts, not merely by love, which is always personal, or at the best tribal, but by the perception of his oneness with each human beinq-Zj^In the practice of mutual oriq^in of our ethical conceptions ; and we can affirm that in the ethical progress of man, mutual support- not mutual struggle — has had the leading part. In its wide extension, even at the pfesent time, ^et also see the best guarantee of a still loftier evolution of our \ race. '

M. C. PiEPERS has published in Natuurkunding Tijdschrift voor Neederlandsch Indie, 1891, Deel L. p. 198 (analyzed in Naturwissenschaftliche Rundschau, 1891, vol. vi. p. 573), interesting researches into the mass-flights of butterflies which occur in Dutch East India, seemingly under the influence of great draughts occasioned by the west monsoon. Such mass-flights usually take place in the first months after the begin- ning of the monsoon, and it is usually individuals of both sexes of Catopsilia {Callidryas) crocale, Cr., which join in it, but occasionally the swarms consist of indi- viduals belonging to three different species of i:he genus Euphcea. Copulation seems also to be the purpose of such flights. That these flights are not the result of concerted action but rather a consequence of imitation, or of a desire of following all others, is, of course, quite possible.

Bates saw, on the Amazon, the yellow and the orange Callidryas "assembling in densely packed masses, sometimes two or three yards in circumference, their wings all held in an upright position, so that the beach looked as though variegated with beds of crocuses." Their migrating columns, crossing the river from north to south, "were uninterrupted, from an early hour in the morning till sunset " {Naturalist on the Amazon, p. 131). Dragon-flies, in their long migrations across the Pampas, come together in countless numbers, and their immense swarms contain individuals belonging to different species (Hudson, Naturalist on the La Plata, pp. \ioseq).

The grasshoppers {Zoniopoda tarsata) are also eminently gregarious (Hudson, /. c. p. 125). Pierre Huber's Les fourmis indigenes (Geneve, 1810), of which a cheap edition was issued in 1861 by Cherbuliez, in the Bibliotheque Genevoise, and of which translations ought to be circulated in cheap editions in every language, is not only the best work on the subject, but also a model of really scientific research. Darwin was quite right in describing Pierre Huber as an even greater naturalist than his father. This book ought to be read by every young naturalist, not only for the facts it contains but as a lesson in the methods of research. The rearing of ants in artificial glass nests, and the test experiments made by subsequent explorers, including Lubbock, will all be found in Huber's admirable little work. Readers of the books of Forel and Lubbock are, of course, aware that both the Swiss professor and the British writer began their work in a critical mood, with the intention of disproving Huber's assertions concerning the admirable mutual- aid instincts of the ants ; but that after a careful investigation they could only confirm them. However, it is unfortunately characteristic of human nature gladly to believe any affirmation concerning men being able to change at will the action of the forces of Nature, but

to refuse to admit well-proved scientific facts tending to reduce the distance between man and his animal brothers. Mr. Sutherland [Origin and Growth of Moral Instinct) evidently began his book with the intention of proving that all moral feelings have originated from parental care and familial love, which both appeared only in warm-blooded animals ; consequently he tries to minimize the importance of sympathy and co-opera- tion among ants. He quotes Biichner's book, Mind in Animals, and knows Lubbock's experiments. As to the works of Huber and Forel, he dismisses them in the following sentence ; " but they [Biichner's in- stances of sympathy among ants] are all, or mostly all, marred by a certain air of sentimentalism . . . which renders them better suited for school books than for cautious works of science, and the same is to be rem,arked [italics are mine] of some of Huber's and Forel's best- known anecdotes" (vol. i, p. 298).

Mr. Sutherland does not specify which "anecdotes" he means, but it seems to me that he could never have had the opportunity of perusing the works of Huber and Forel. Naturalists who know these works find no " anecdotes " in them. The recent work of Professor Gottfried Adlerz on the ants in Sweden {Myrmecologiska Studier : Svenska Myroroch des Lefnadsfdrhdllanden, in Bihan till Sven- ska Akadem.iens Handlingar, Bd. xi. No. 18, 1886) may be mentioned in this place. It hardly need be said that all the observations of Huber and Forel concerning the mutual-aid life of ants, including the one concerning the sharing of food, felt to be so striking by those who previously had paid no attention to the subject, are fully confirmed by the Swedish professor (pp. 136-137).

Professor G. Adlerz gives also very interesting experiments to prove what Huber had already observed ; namely, that ants from two different nests do not always attack each other. He has made one of his experiments with the ant, Tapinoma erraticum. Another was made with the common Rufa ant. Taking a whole nest in a sack, he emptied it at a distance of six feet from another nest. There was no battle, but the ants of the second nest began to carry the pupae of the former. As a rule, when Professor Adlerz brought together workers with their pupae, both taken from different nests, there was no battle ; but if the workers were without their pupae, a battle ensued (pp. 185-186).

He also completes Forel's and MacCook's observa- tions about the "nations" of ants, composed of many nests, and, taking his own estimates, which brought him to take an average of 300,000 Formica exsecta ants in each nest, he concludes that such " nations " may reach scores and even hundreds of millions of inhabitants, Maeterlinck's admirably written book on bees, although it contains no new observations, would be very useful, if it were less marred with metaphysical "words."

Audubon's Journals {Audubon and his Journals, New York, 1898), especially those relating to his life on the coasts of Labrador and the St. Lawrence river in the thirties, contain excellent descriptions of the nesting associations of aquatic birds. Speaking of "The Rock," one of the Magdalene or Amherst Islands, he wrote : — "At eleven I could distinguish its top plainly from the deck, and thought it covered with snow to the depth of several feet ; this appearance

existed on every portion of the flat, projecting shelves." But it was not snow : it was gannets, all calmly seated on their eggs or newly-hatched brood — their heads all turned windwards, almost touching each other, and in regular lines. The air above, for a hundred yards and for some distance round the rock, " was filled with gannets on the wing, as if a heavy fall of snow was directly above us." Kittiwake gulls and foolish guillemots bred on the same rock {^Journals, vol. i, pp.

In sight of Anticosti Island, the sea " was literally covered with foolish guillemots and with razor- billed auks {Alca torva)" Further on, the air was filled with velvet ducks. On the rocks of the Gulf, the herring gulls, the terns (great, Arctic, and probably Foster's), the Tringa pusilla, the sea-gulls, the. auks, the Scoter ducks, the wild geese {Anser canadensis), the red-breasted merganser, the cormor- ants, etc., were all breeding. The sea-gulls were extremely abundant there ; " they are for ever harass- ing every other bird, sucking their eggs and devouring their young;" "they take here the place of eagles and hawks."

On the Missouri, above Saint Louis, Audubon saw, in 1843, vultures and eagles nesting in colonies. Thus he mentioned " long lines of elevated shore, surmounted by stupendous rocks of limestone, with many curious holes in them, where we saw vultures and eagles enter towards dusk " — that is, Turkey buzzards [Cathartes aura) and bald eagles {Halia'etus leuco- cephalus), E. Coues remarks in a footnote (vol. i. p. One of the best breeding-grounds along the British shores are the Fame Islands, and one will find in Charles Dixon's work. Among the Birds in Northern Shires, a lively description of these grounds, where scores of thousands of gulls, terns, eider-ducks, cor- morants, ringed plovers, oyster-catchers, guillemots,

and puffins come together every year. " On approach- ing some of the islands the first impression is that this gull (the lesser black-backed gull) monopolizes the whole of the ground, as it occurs in such vast abundance. The air seems full of them, the ground and bare rocks are crowded ; and as our boat finally grates against the rough beach and we eagerly jump ashore all becomes noisy excitement — a perfect babel of protesting cries that is persistently kept up until we leave the place" (p. 219).

That the sociability of animals was greater when they were less hunted by man, is confirmed by many facts showing that those animals who now live isolated in countries inhabited by man continue to live in herds in uninhabited regions. Thus on the waterless plateau deserts of Northern Thibet Prjevalsky found bears living in societies. He mentions numerous " herds of yaks, khulans, antelopes, and even bears." The latter, he says, feed upon the extremely numerous small rodents, and are so numerous that, " as the natives assured me, they have found a hundred or a hundred and fifty of them asleep in the same cave " ( Yearly Report of the Russian Geographical Society for 1885, p. 1 1 ; Russian). Hares \Lepus Lehmani) live in large societies in the Transcaspian territory (N. Zaru- dnyi, Recherches zoologiques dans la contrie Trans- caspienne, mBull. Soc. Natur. Moscou, 1889, 4). The small Californian foxes, who, according to E. S. Holden, live round the Lick observatory "on a mixed diet of Manzanita berries and astronomers' chickens "

Some very interesting instances of the love of society among animals have lately been given by Mr. C. J. Cornish {Animals at Work and Play, London, 1896). All animals, he truly remarks, hate solitude. He gives also an amusing instance of the habit of the prairie dogs of keeping sentries. It is so great that they always keep a sentinel on duty, even at the London Zoological Garden, and in the Paris Jardin d'Acclimatation (p. 46). Professor Kessler was quite right in pointing out that the young broods of birds, keeping together in autumn, contribute to the development of feelings of sociability. Mr. Cornish. (Animals at Work and Play) has given several examples of the plays of young mammals, such as, for instance, lambs playing at " follow my leader," or at " I'm the king of the castle," and their love of steeplechases ; also the fawns playing a kind of " cross-touch," the touch being given by the nose. Altogether we have, moreover, the excellent work by Karl Gross, The Play of Animals.

Hudson, in his Naturalist on the La Plata (Chapter III.), has a very interesting account of a sudden increase of a species of mice and of the consequences of that sudden " wave of life." " In the summer of 1872-73," he writes, "we had plenty of sunshine, with frequent showers, so that the hot months brought no dearth of wild flowers, as in most years." The season was very favourable for mice, and "these prolific little creatures were soon so abundant that the dogs and the cats subsisted almost exclusively on them. Foxes, weasels and opossums fared sumptuously ; even the insectivorous armadillo took to mice-hunting." The fowls became quite rapacious, " while the sulphur tyrant-birds (Pitangus) and the Guira cuckoos preyed on nothing but mice." In the autumn, countless numbers of storks and of short-eared owls made their appear- ance, coming also to assist at the general feast. Next came a winter of continued drought ; the dry grass was eaten, or turned to dust ; and the mice, deprived of cover and food, began to die out. The cats sneaked back to the houses ; the short-eared owls — a ,wandering species — left ; while the little burrowing owls became so reduced as scarcely to be able to fly, " and hung about the houses all day long on the look-out for some stray morsel of food." Incredible numbers of sheep and cattle perished the same winter, during a month of cold that followed the drought. As to the mice', Hudson makes the remark that " scarcely a hard-pressed remnant remains after the great reaction, to continue the species."

This illustration has an additional interest in its showing how, on flat plains and plateaus, the sudden increase of a species immediately attracts enemies from other parts of the plains, and how species unpro- tected by their social organization must necessarily succumb before them. Another excellent illustration in point is given by the same author from the Argentine Republic. The coypu {Myiopotamus coypu) is there a very com- mon rodent — a rat in shape, but as large as an otter. It is aquatic in its habits and very sociable. " Of an evening," Hudson writes, "they are all out swimming and playing in the water, conversing together in strange tunes, which sound like the moans and cries of wounded and suffering men. The coypu, which

has a fine fur under the long coarse hair, was largely- exported to Europe ; but some sixty years ago the Dictator Rosas issued a decree prohibiting the hunt- ing of this animal. The result was that the animals increased and multiplied exceedingly, and, abandon- ing their aquatic habits, they became terrestrial and migratory, and swarmed everywhere in search of food. Suddenly a mysterious malady fell on them, from which they quickly perished, and became almost extinct" (p. 12).

Extermination by man on the one side, and con- tagious diseases on the other side, are thus the main checks which keep the species down — not competition for the means of existence, which may not exist at all. Facts, proving that regions enjoying a far more congenial climate than Siberia are equally under- populated, could be produced in numbers. But in Bates' well-known work we find the same remark concerning even the shores of the Amazon river.

" There is, in fact," Bates wrote, " a great variety of mammals, birds and reptiles, but they are widely scattered and all excessively shy of man. The region is so extensive and uniform in the forest-clothing of its surface, that it is only at long intervals that animals are seen in abundance, where some particu- lar spot is found which is more attractive than the others" {Naturalist on the Amazon, 6th ed., p. 31). This fact is the more striking as the Brazilian fauna, which is poor in mammals, is not poor at all in birds, and the Brazilian forests afford ample food for birds, as may be seen from a quotation, already given on a previous page, about birds' societies. And yet, the forests of Brazil, like those of Asia and Africa, are not over- populated, but rather under-populated. The same is true concerning the pampas of South America, about which W. H. Hudson remarks that it is really astonish- ing that only one small ruminant should be found on

this immense grassy area, so admirably suited to herbivorous quadrupeds. Millions of sheep, cattle and horses, mtroduced by man, graze now, as is known, upon a portion of these prairies. Land-birds on the pampas are also few in species and in numbers. Numerous examples of such adaptations can be found in the works of all field-naturalists. One of them, very interesting, may be given in the hairy armadillo, of which W. H. Hudson says, that " it has struck a line for itself, and consequently thrives, while its congeners are fast disappearing. Its food is most varied. It preys on all kinds of insects, dis- covering worms and larvae several inches beneath the surface. It is fond of eggs and fledglings ; it feeds on carrion as readily as a vulture ; and, failing animal food, it subsists on vegetable diet — clover, and even grains of maize. Therefore, when other animals are starving, the hairy armadillo is always fat and vigorous" {JSfaluralist on the La Plata, p. 71).

The adaptivity of the lapwing makes it a species of which the range of extension is very wide. In England, it " makes itself at home on arable land as readily as in wilder areas." Ch. Dixon says in his Birds of Northern Shires (p. 67), "Variety of food is still more the rule with the birds of prey." Thus, for instance, we learn from the same author (pp. 60, 65), " that the hen harrier of the British moors feeds not only on small birds, but^so on moles and mice, and on frogs, lizards and insects, while most of the smaller falcons subsist largely on insects."

The very suggestive chapter which W. H. Hudson gives to the family of the South American tree- creepers, or woodhewers, is another excellent illus- tration of the ways in which large portions of the animal population avoid competition, while at the same time they succeed in becoming very numerous in a given region, without being possessed of any of the weapons usually considered as essential in the struggle for existence. The above family covers an immense range, from South Mexico to Patagonia, and no fewer than 290 species, referable to about 46 genera, are already known from this family, the most striking feature of which is the great diversity of habits of its members. Not only the different genera and the different species possess habits pecu- liarly their own, but even the same species is often found to differ in its manner of life in different localities. "Some species oi Xenops and Magarornis, like wood- peckers, climb vertically on tree-trunks in search of insect prey, but also, like tits, explore the smaller twigs and foliage at the extremity of the branches ; so that the whole tree, from the root to its topmost foliage, is hunted over by them. The Sclerurus, although an inhabitant of the darkest forest, and pro- vided with sharply-curved claws, never seeks its food on trees, but exclusively on the ground, among the decaying fallen leaves ; but, strangely enough, when alarmed, it flies to the trunk of the nearest tree, to which it clings in a vertical position, and, remaining silent and motionless, escapes observation by means of its dark protective colour." And so on. In their nesting habits they also vary immensely. Thus, in one single genus, three species build an oven-shaped clay-nest, a fourth builds a nest of sticks in the trees, and a fifth burrows in the side of a bank, like a kingfisher.

Now, this extremely large family, of which Hudson says that " every portion of the South American con- tinent is occupied by them ; for there is really no climate, and no kind of soil or vegetation, which does not possess its appropriate species, belongs" — to use his own words — " to the most defenceless of birds." Like the ducks which were mentioned by Syevertsoff (see in the text), they display no powerful beak or claws ; " they are timid, unresisting creatures, with- out strength or weapons ; their movements are less quick and vigorous than those of other kinds, and their flight is exceedingly feeble." But they possess — both Hudson and Asara observe — " the social dis- position in an eminent degree," although "the social habit is kept down in them by the conditions of a life which makes solitude necessary." They cannot make those large breeding associations which we see in the sea-birds, because they Hve on the tree-insects, and they must carefully explore separately every tree — which they do in a most business-like way ; but they con- tinually call each other in the woods, " conversing with one another over long distances ; " and they associate in those " wandering bands " which are well known from Bates' picturesque description, while Hudson was led to believe " that everywhere in South America the Dendrocolaptids are the first in combining to act in concert, and that the birds of other families follow their march and associate with them, knowing from experience that a rich harvest may be reaped," It hardly need be added that Hudson pays them also a high compliment concern- ing their intelligence. Sociability and intelligence always go hand in hand.