Page:Popular Science Monthly Volume 84.djvu/413

Rh It is a truth that loses none of its force by repetition that in laboratory observation of animals, the laboratory conditions do not always accurately represent the conditions in nature, and that the deportment of an animal in the laboratory may not be exactly the same as its deportment in nature. The failure of some relatively high animals to breed in captivity is a case in point, and this again calls attention to the importance of a group of afferent impulses rather than a single impulse in determining the response of animals. Some subtle influence of the natural environment is lacking in the conditions obtaining in captivity, and the normal deportment of the animals is modified in at least one important detail. Other animals have a nervous system of sufficient plasticity to adjust themselves to the changed conditions of the laboratory or zoological garden. But the laboratory experimenter is now, and will be for some time to come, dependent upon the data of close and accurate observers of animal life in the field for his basis of comparison. And until the laboratory worker is certain that the deportment observed in the laboratory corresponds to that in nature, his analysis is not biologically accurate.

It is probably true, as Professor Cockerell suggests, that no man will ever be able accurately to tell the complete story of Wallace's life work, even on its biological side alone, using the word in its widest sense. It is an evidence of the genius of Darwin and of Wallace that each was able to get such a fundamental grasp of the phenomena of nature as to afford problems for workers in other lines apparently far removed from their own. The experimental physiologist has had relatively little to say in-regard to evolution as yet, and is perhaps in no position to settle dogmatically any particular problem now. But physiology has a direct contribution of interest to the worker in certain phases of a much wider problem. Specialties multiply, new and confusing terminologies develop, and the point of view ever tends to become narrow. Biologists pursuing one specialty have more and more difficulty in communicating to biologists in other lines of work, the particular results in their own. And biologists are almost unintelligible to workers in physics and chemistry. Yet science is a unit, and there can be no lasting truth developed in one field unless it is in accord with truth in every other field. The task of finding out what other workers have to offer us is a huge and even insuperable one under present conditions. Some hope of relief may be held out when the biologists get some of their great generalizations reduced to simpler form, and consequently intelligible to the scientific multitude. At present, the theory of evolution seems to be the most promising common meeting place to which biologists in all lines of work may bring their contributions for the judgment and criticism of their brother workers.