214 Inheritance of Acquired Characters 



whose power of growth stands in exact proportion with 

 their length? Would the shorter fingers therefore have 

 a phylogenetic tendency to become constantly still shorter, 

 and the longer fingers a tendency to become steadily 

 longer yet? If that were so it would lead directly into 

 this absurdity, that the formation in phylogeny of new 

 organs or of new structures in general could never have 

 any commencement, since originally their determinants, 

 just because of the very smallness of these formations, 

 must have been provided with only a very small power 

 of growth and therefore could never progress side by 

 side with determinants which must in any case be 

 stronger since they belong to organs or structures already 

 developed. 



If on the contrary this is not the case and cannot be 

 the case because it contains an unavoidable contradiction, 

 then the determinants of any degenerated organ what- 

 ever, such for example as the hind leg of the immediate 

 ancestor of the whale, cannot be regarded as feebler, but 

 must rather be regarded as qualitatively different from 

 those of the complete organ. Consequently there cannot 

 exist for the degenerated organ any phylogenetic tendency 

 to become still more rudimentary. 



Weismann would give, as we have said, a quite 

 similar explanation of co-ordinated variations : 



If there were, for example an increase of the weight 

 of the head, as a direct result let us suppose of natural 

 selection, certain muscles of the body after having 

 received an initial impulse from natural selection itself, 

 would acquire a phylogenetic tendency to grow pari passu 

 with the weight of the head. For the first operation of 

 natural selection would be to eliminate individuals whose 

 muscles were too feeble. Then even if we suppose that 



