THE GROWTH OF BIOLOGICAL IDEAS 163 



evolution was delayed until after the product of the monas- 

 tery had been brought into the light of day in 1900. 



The geographic distribution of organisms, their habitats, 

 foods, and "enemies" seem relatively simple matters for study, 

 and one might have looked for the development of these 

 branches of biology early in the history of science. It is true 

 that Linnaeus and other eighteenth century biologists re- 

 corded the habitats of the plants they described, and Captain 

 Cook took biologists with him on his great voyages of explora- 

 tion; but no serious attempt was made to draw general con- 

 clusions or to found a special branch of biology covering the 

 natural conditions of life of plants and animals. It was not 

 until 1858 that an ornithologist, P. L. Sclater, made an at- 

 tempt to divide the world into zoological regions. The theory 

 of evolution then gave an impetus to such studies. It was 

 necessary to find not only what organisms lived where, but 

 how that particular distribution had come about in the course 

 of geological time. In the seventies Alfred Russel Wallace, 

 himself a great traveler, rounded off his general contribution 

 to the theory of evolution by a particular study of geographic 

 distribution. His zoological regions, founded for the most 

 part on those of Sclater, have retained much of their validity 

 to the present day. Wallace's line, w^hich he drew with such 

 remarkable accuracy through the map of the East Indian 

 archipelago, still separates the extraordinary fauna of the 

 Australasian region from the animals of eastern Asia. 



The study of the home life of organisms or ecology, as it 

 eventually came to be called, still remained in a primitive 

 state. Darwin himself was a first-rate ecologist, as every 

 reader of The Origin of Species must know. Academic biolo- 

 gists, however, continued to leave the subject alone, as though 

 mere natural history were beneath their notice. Not suffi- 

 cient attention was paid to the fact that plants and animals 

 have their particular structure and functions simply because 

 their ancestors lived in certain habitats, were subject to the 

 rigors of certain climates, fed on certain foods, and were 

 liable to attack by certain other organisms. It was inde- 



