ON THE VITALLSTIC VIEW OF NATURE. 415 



outdoor research, into the arena of real life. On this 

 I dwelt in the last chapter. Ideas of a cognate kind 

 had already emanated from other schools, such as that 

 of Liebig, — the circulation of life in the different pro- 

 vinces of nature, the interdependence of dillerent species 

 of living things. Isolated investigations, like those of 

 Gartner and Sprengel, of Iluber and Lubbock, on insect 

 life, or of bacteriologists like Pasteur and Boussingault 

 on fermentation and fertilisation, received a fitting place 

 as important chapters in the economics of nature. The ss. 



Oi'K'anisation 



problem of life became twofold — the life of the com- andiudivid- 



■^ nation. 



munity and the life of the individual : organisation and 

 individuation. Two great (juestions presented them- 

 selves : What is an individual ? what is a society of 

 individuals 1 Physiologists were from of old accustomed 

 to ask the former ; economists like Rousseau and Adam 

 Smith had asked the latter question. Both now became 

 questions for the biologist. Physiology and economics 

 joined hands. In isolated instances, as in those of Liebig 

 and von Baer, these two interests had already been united. 

 The real meaning and reason of this union now Ijecame 

 clear to every one : it revealed itself as founded on the 

 two characteristic features of life— individuality and co- 

 operation. With the exception of the strong emphasis so. 



, X • 1 ■ • 1 Biology and 



put l)y Liebig on tfie latter side of natural, notably loonomics. 

 organic processes, biologists before Darwin liad mainly 

 studied the phenomena of individual life. In two special 

 directions — in embryology and in the cellular theory — 

 they had made great progress. 1 have already treated 

 of these advances in their bearing ujton morphology, the 

 study of forms, and upon genesis, the study of change 



