26 (iii) Weismann's counter -doctrine 



that the mingling of ancestral characters in 

 sexual reproduction is suflScient to provide 

 endless variations on which natural selection 

 can work, thus rendering it also needless. 

 Continuity of germ-plasm in some sense is 

 an obvious fact in any case ; and Harvey's 

 position, omne vivum e vivo, is one that no 

 biologist is concerned practically to deny. 

 What Weismann means by germinal con- 

 tinuity, however, is such an absolute conti- 

 nuity of the germ-plasm as entails its absolute 

 discontinuity from the body-plasm. Let the 

 changes acquired by the parents be what 

 they may, they can, he maintains, make no 

 difference to the offspring. The circular 

 character of the argument is here again 

 apparent. Till the impossibility of the 

 Lamarckian position is proved, germinal 

 continuity or continuity of the germ-plasm 

 may exist, but the absolute isolation of this 



