DARWINISM DEFENDED. 145 



forward. And so with many other complex specialisations, 

 although in almost all these cases it is necessary, as Darwin 

 says, to let the reason conquer the imagination. That is, the 

 reasoned explanation explains, although one recoils con- 

 stantly before the almost inconceivable actuality of the 

 phenomenon. 



Plate has recognised this objection as one of the really 

 weighty ones and has given much attention to its considera- 

 tion. His conclusion is that it is necessary to rely to a 

 ereater or less extent on the Lamarckian factor of the 



o 



inheritance of somatogenic characters acquired in the life- 

 time of the individual through the effects of use, or disuse, 

 or other functional stimuli. This is, of course, direct aban- 

 donment of the position maintained by such strict selection- 

 ists as Weismann and Wallace, although Weismann himself, 

 in order to answer the objection without having recourse 

 to reliance on Lamarckian factors, introduces his new 

 theory or hypothesis of germinal selection to aid natural 

 selection in the difficulty presented by the objection. Lloyd 

 Morgan's 9 answer to this objection consists chiefly of the 

 formulation of the theory of orthoplasy (explained in chapter 

 viii of this book). It is, briefly, that every organism, from 

 its somatic and germinal aspects, exhibits two tendencies 

 of variability. The somatic variability is determined largely 

 or at least modified largely by environmental influences ; 

 therefore those organisms whose somatic tendency is pre- 

 dominantly plastic w T ill survive under altered conditions of 

 environment, where those organisms of a less easily mod- 

 ifiable tendency will be eliminated. Now if somatic changes 

 rarely or never become germinal, i.e., are inherited, the mod- 

 ifications of the parental organisms cannot be transmitted 

 to their offspring, but those offspring that happen to be 

 endowed with germinal variations in the same direction 

 as the acquired but not transmitted modifications would 

 start their life with a predisposition favourable to their 



