The main, if not the only direct service of zoology has been given through the subject of entomology. Although some of the most dangerous enemies of plants are still beyond control, such as the boll weevil, yet their habits are understood and the crops on which they prey can still be grown with only a fraction of the loss that would be sustained had the habits and life history of such pests not been made known. Other pests have either been eradicated or rendered so nearly controllable as to permit of our safely disturbing the balance of nature by devoting large areas to special crops of such plants as are not encouraged in the natural state.
The Zoologists' Inability to Aid Breeders
We should naturally expect zoology to throw considerable light upon the laws of heredity and upon possible methods of so modifying forms and functions of our animals as to give us more intelligent control of those great factors in agriculture. It is true that a most wonderful improvement of all classes of farm animals has been effected; from a few unpromising native stocks, numerous and distinct varieties have been evolved, each one having distinctive characters of value, either in special adaptability to specific conditions and systems of agriculture, or in capacity to yield a superior product, or, as is true of many breeds, combining some degree of excellence in both respects.
In this fascinating and valuable work, however, there has been little or nothing that could properly be called scientific, unless we should regard as science an accumulation of facts regarding occurrences the explanations of which have not been attempted by the breeders and not altogether successfully undertaken, as yet, by the zoologists.
The fact that zoology has given so little that could be utilized by the breeder is no reflection upon the zoologists. Their problem has been a difficult one, and until a science assumes a form of some definiteness, it is too early to expect any of its principles to be followed out into their operation in economic affairs, particularly when, as in zoology, supposed facts are being dethroned and the evolution of the science seems hardly begun.
The discoverer of important principles can not be expected to also assume the duty of interpreting his science to practise. He works for the acquisition of knowledge and the understanding of natural law in its broadest relations and is seldom qualified to give a scientific aspect to productive labors, even if willing to attempt such a task.
It can truthfully be stated that biology, as one of the sciences, is the newest and least definite of them all, unless we except, perhaps, psychology. This is not because great minds have not been occupied with it, for what other study has engaged such illustrious and widely-known men as Darwin and Wallace and Spencer and Galton and Huxley of England, and such as Lamarck in France and Weismann in Germany?