Palingenesis toith heredity 17 



approximately the same time in the two 

 cases — that of a single persisting individual 

 and that of a continuous succession of 

 perishing individuals — the recapitulatory 

 process, peculiar to the second case, proves 

 to be vastly more rapid. It took thousands 

 of years, say, to produce the first chicken, 

 but the hen's egg reaches the same level in 

 three weeks. To be sure the recapitulation 

 is not precise and complete in every detail ; 

 yet most biologists, I believe, allow that it is 

 very full and substantial. Nevertheless even 

 in the most complex organisms far the 

 greater part of it is accomplished within a 

 year. How may we account for this extra- 

 ordinary brevity in the repetition of a process 

 that took so long at first 1 The consideration 

 of this question in the light of our preliminary 

 investigation may lead us towards a solution 



of our problem. 



2 



