62 WARFARE IN THE HUMAN BODY 



inherited living matter accounts for every organ as it 

 appears ; while all changes are due to obscure variations 

 of an advantageous kind which give the survivors in the 

 struggle a better chance. On analysis, such opinions do 

 not seem truly scientific, for the " nature " of the germ- 

 plasm can barely be distinguished from the directing 

 entelechy of Driesch, and if the Weismannian cloud of 

 ids and biophors is now somewhat condensed, the magic 

 determinant still remains in a concealed vitalism which is 

 exactly analogous, as regards the organism, to pantheism 

 as regards the universe. Nor, if we are told with certainty 

 that altered characteristics are not transmitted, is the 

 theory of small advantageous variations much more 

 satisfactory, if we know neither how they come, nor how 

 they are inherited. To say so much must not be regarded 

 as treating with disrespect its great author, without whom 

 we might still be wandering in the barren field of teleology. 

 To regard these theories as hasty and, perhaps, un- 

 sound explanations is not to accept without scrutiny 

 the theory of the transmission of acquired, or modified, 

 characteristics. Though this is a view that can be 

 defended on the physico-chemical grounds of catalysts 

 which are measurable determinants of a really scientific 

 order, experiments to prove the fact must take a very 

 long time, and we are compelled to rely on other methods 

 of proof. That the experiments of Tower and Kammerer, 

 for instance, suggest the transmission of modifications 

 cannot be denied. Such as oppose the general view that 

 the environment has thus an inheritable moulding influence 

 on the organism, seem to reply that those are only rare 

 and doubtful cases, whereas the theory of inherited 

 advantageous variations, whether continuous or dis- 

 continuous, can be made responsible for the whole of the 



