INTRODUCTION xv 



possible by simple liquid diffusion to reproduce in ordered and 

 regular succession complicated movements like those observed 

 in the karyokinesis of the living cell. 



The essential character of the living being is its Form. 

 This is the only characteristic which it retains during the 

 whole of its existence, with which it is born, which causes its 

 development, and disappears with its death. The task of 

 synthetic biology is the recognition of those physico-chemical 

 forces and conditions which can produce forms and structures 

 analogous to tliose of living beings. This is the subject of the 

 chapter on Morphogenesis. 



The last chapter deals with the doctrine of Evolution. 

 The chain of lite is of necessity a continuous one, from the 

 mineral at one end to the most complicated organism at the 

 other. We cannot allow that it is broken at any point, or that 

 there is a link missing between animate and inanimate nature. 

 Hence the theory of evolution necessarily admits the physico- 

 chemical nature of life and the fact of spontaneous generation. 

 Only thus can the evolutionary theory become a rational one, 

 a stimulating and fertile inspirer of research. We seek tor the 

 physico-chemical forces which produce forms and structures 

 analogous to those of living beings, and phenomena analogous 

 to tliose of life. We study the alterations in environment 

 which modify these forms, and we seek in the past history of 

 our planet tor those natural phenomena which have brought 

 these physico-chemical forces into play. In this way we may 

 find the road which will, we hope, lead some day to the 

 discovery of the origin and the evolution of life upon the 

 earth. 



