426 LAWS OF MULTIPLICATION. 



articulate animals never multiply asexually after this simplest; 

 method, and while they are characterized in the mass by the 

 cessation of agamogenesis of every kind, there nevertheless 

 occur in a few of their small species, those higher forms of 

 dgamogenesis known as parthenogenesis, pseudo-partheno 

 genesis and internal metagenesis ; and that by these some of 

 them multiply very rapidly. Hereafter we shall find, in the 

 interpretation of these anomalies, further support for the 

 general doctrine. 



To the above evidence has to be added that which the 

 Vertebrata present. This may be very briefly summed up. 

 On the one hand, this class, whether looked at in the aggre 

 gate or in its particular species, immensely exceeds all other 

 classes in the sizes of its individuals ; and on the other hand, 

 agamogenesis under any form is absolutely unknown in it, 



337. Such are a few leading facts serving to show how 

 deduction is inductively verified, in so far as the anta 

 gonism between Growth and Asexual Genesis is con 

 cerned. In whatever way we explain this opposition of 

 the integrative and disintegrative processes, the facts and 

 their implications remain the same. Indeed we need not 

 commit ourselves to any hypothesis respecting the physical 

 causation : it suffices to recognize the results under their 

 most general aspects. We cannot help admitting there are 

 at work these two antagonist tendencies to aggregation and 

 separation ; and we cannot help admitting that the propor 

 tion between the aggregative and separative tendencies, must 

 in each case determine the relation between the increase in 

 bulk of the individual and the increase of the race in number. 



The antithesis is as manifest a posteriori as it is neces- 

 saiy d priori. While the minutest organisms multiply 

 asexually in their millions ; while the small compound 

 types next above them thus multiply in their thousands ; 

 while larger and more compound types thus multiply in their 

 hundreds and their tens ; the largest types do not thus 



