INTRODUCTION 11 



the adult, the parts that are cells as well as the parts 

 built of many cells. As, however, during visible 

 development the parts of the embryo undergo 

 many changes of position and metamorphoses, 

 Weismann is compelled to make the assumption 

 that the germ, as a micro-organism, is not simply 

 a miniature of the adult, but that its minute 

 particles have an arrangement totally different from 

 that of the corresponding parts in the adult 



organism. 



The second point is the origin of each new 

 generation. To explain the continuity of develop- 

 ment, the old evolutionists held that the genera- 

 tions lay enfolded one within another. Weismann 

 avoids this difficulty by endowing his germs with 

 divisibility, but he gives us no proof that division 

 could possibly take place in the case of structures 

 composed of innumerable particles built up into a 

 definite and most complicated architectural system. 



Although the new evolution differs from the old 



o 



in the points mentioned above, the two theories 

 obviously agree very closely in the nature of their 

 arguments and conclusions. When, to satisfy our 

 craving for causality, biologists transform the visible 

 complexity of the adult organism into a latent com- 

 plexity of the germ, and try to express this by 

 imaginary tokens, by minute and complicated 

 particles cohering into a system, they are making 

 a phantasmal image which, indeed, apparently may 

 satisfy the craving for causality (to satisfy which 

 it was invented), but which eludes the control of 

 concrete thought, by dealing with a complexity 



