108 EVOLUTION 



first of these views is the neo-Darwinian; while 

 the second savours of neo-Lamarckianism ; 

 but here, happily, is a case in which the recent 

 admirable eirenicon of Lloyd Morgan, Osborn 

 and Baldwin (discussed in Chapter VI) may 

 be conveniently applied. According to this, 

 the modifications of the individual in response 

 to environment, to use and disuse, in them- 

 selves non-heritable though they may be, may 

 yet serve as the nurse and shield and selective 

 vantage-ground for germ-variations in the 

 same direction. With this two-fold process 

 at work, in germs and in developing adults, 

 the frequent development of parasitic shoots 

 upon the tree of life becomes a less perplexing 

 marvel. 



Another interest of this subject is the way 

 in which it invites that comparison of the 

 natural and the social world which has always 

 been so fascinating, and, as we maintain 

 from opening to close of this volume, also so 

 fruitful. The naturalist and physician almost 

 forget that the word parasite was originally 

 a social epithet; but the many critics of human 

 society are using the comparison more and 

 more frequently, of course often in mere vague 

 abuse, but sometimes keenly also. Notable 

 in this connection is the collaboration of 

 Professor Massart, a biologist of Brussels, with 



