REASONS FOR AFFIRMATIVE ANSJVER 195 



has been inheritance of acquired characters, or there has been no 

 evolution." * 



Haeckel is so convinced for the affirmative that he stakes 

 his particular form of rehgion upon it, asserting that " belief 

 in the inheritance of acquired characters is a necessary axiom 

 of the monistic creed " ; and what may sound to some even more 

 serious is his declaration that, rather than agree with Weismann 

 in denying the inheritance of acquired characters, " it would be 

 better to accept a mysterious creation of all the species as 

 described in the Mosaic account." 



Sir William Turner has said that " to reject the influence which 

 the use and disuse of parts may exercise, both on the individual 

 and on his offspring, is like looking at an object with only a single 

 eye " — which is not perhaps a very emphatic condemnation, 

 since most microscopic research is monocular. Moreover, the 

 doyen of British anatomists does not state the case with his 

 usual precision. 



Why is the Afl5rmatiYe Position so widely held? — Even 

 in regard to our own muscular and nervous systems, we are 

 familiar with illustrations of the fact that practice increases 

 capacity, and that desuetude is apt to be followed by loss of 

 power. A force de forger on devient forgeron. Organs improve 

 with the using and deteriorate in disuse. We are also well aware 

 that changes in the environment or conditions of life, and notably 

 in our food, cause changes in our body. It seems a " natural " 

 assumption to suppose that these gains and losses and changes 

 may be in some degree transmissible. 



Apart from the " naturalness " of this assumption, there are 

 probably four reasons why the affirmative position is so widely 

 held: 



(i) There are many facts which suggest modification-inheritance 



* The italics are ours. See Herbert Spencer, " The Inadequacy of 

 Natural Selection," Contemporary Review, February and March, 1893- 

 Appendix B, Principles of Biology, 2nd ed. vol. i. 1898, p. 621. 



