dispositions. Colonies differ, as every beekeeper knows, but probably the members composing it differ very little. The community interests shape all alike. Is it not the same in a degree among men? Does not solitude bring out a man's peculiarities and differentiate him from others? The more one lives alone, the more he becomes unlike his fellows. Hence the original and racy flavor of woodsmen, pioneers, lone dwellers in nature's solitudes. Thus isolated communities develop characteristics of their own. Constant intercommunication, the friction of travel, of streets, of books, of newspapers, make us all alike; we are, as it were, all pebbles upon the same shore, washed by the same waves.
Among the larger of vertebrate animals, I think, one might reasonably expect to find more individuality among those that are solitary than among those that are gregarious; more among birds of prey than among water-fowl, more among foxes than among prairie-dogs, more among moose than among sheep or buffalo, more among grouse than among quail. But I do not know that this is true.
Yet among none of these would one expect to find the diversity of individual types that one finds among men. No two dogs of the same breed will be found to differ as two men of the same family often differ. An original fox or wolf or bear or beaver or crow or crab—that is, one not merely different from his fellows, but obviously superior to them, differing from them as a master mind differs from the ordinary mind,—I think, one need not expect to find. It is quite legitimate for the animal-story writer to make the most of the individual differences in habits and disposition among the animals; he has the same latitude any other story-writer has, but he is bound also by the same law of probability, the same need of fidelity to nature. If he proceed upon the theory that the wild creatures have as pronounced individuality as men have, that there are master minds among them, inventors and discoverers of new ways, born captains and heroes, he will surely "o'erstep the modesty of nature."
The great diversity of character and capacity among men doubtless arises from their greater and more complex needs, relations, and aspirations. The animals' needs in comparison are few, their relations simple, and their aspirations nil. One cannot see what could give rise to the individual types and exceptional endowments that are often claimed for them. The law of variation, as I have said, would give rise to differences, but not to a sudden reversal of race habits, or to animal geniuses.
The law of variation is everywhere operative—less so now, no doubt, than in the earlier history of organic life on the globe. Yet nature is still experimenting in her blind way, and hits upon many curious differences and departures. But I suppose if the race of man were exterminated, man would never arise again. The law of evolution could not again produce him, nor any other species of animal.
This principle of variation was no doubt much more active back in geologic time, during the early history of animal life upon the globe, than it is in this late age. And for the reason that animal life was less adapted to its environment than it is now the struggle for life was sharper. Perfect adaptation of any form of life to the conditions surrounding it seems to check variability. Animal and plant life seems to vary more in this country than in England because the conditions of life are harder. The extremes of heat and cold, of wet and dry, are much greater. It has been found that the eggs of the English sparrow vary in form and color more in the United States than in Great Britain. Certain American shells are said to be more variable than the English. Among our own birds it has been found that the "migratory species evince a greater amount of individual variation than do non-migrating species" because they are subject to more varying conditions of food and climate. I think we may say, then, if there were no struggle for life, if uniformity of temperature and means of subsistence everywhere prevailed there would be little or no variation and no new species could arise. The causes of variation seem to be the inequality and imperfection of things; the pressure of life is unequally distributed, and this is one of nature's ways that accounts for much that we see about us.
