i 9 4 TRANSMISSION OF ACQUIRED CHARACTERS 



quired characters may be, and sometimes are, transmitted, and 

 that the speculations of the Weismann school of naturalists are 

 unfounded." 



But perhaps this widespread opinion does not mean so much 

 as it seems ; for it is very difficult to get busy practical men to 

 take the trouble to appreciate an exact distinction such 

 as is involved in the phrase, " the inheritance of an acquired 

 character." 



Against the opinion quoted we may balance that of an ex- 

 perienced botanical physiologist, Prof. MacDougal. "Despite 

 general assertions to the contrary, no evidence has yet been 

 obtained to prove that the influence of tillage, ' cultivation,' 

 or the mere pressure of environment factors has produced any 

 permanent changes in hereditary characters of unified strains 

 of plants." 



Great Variety of Opinion. — There is little to be gained by a 

 citation of opinions, for there are equally authoritative names 

 on both sides. But there are some points of interest. Thus we 

 have already noticed that the scepticism as to the inheritance 

 of acquired characters is not a modern fad. It is also note- 

 worthy that, while the majority of zoologists disbelieve in modi- 

 fication-inheritance, the reverse seems to be the case with 

 botanists. Is this because modifications are even more marked 

 and more recurrent in plants than in animals, or because the 

 distinction between soma and germ-plasm is much less definite 

 in plants than in animals ? 



But there is this use at least in noting the discrepancy of 

 opinions, that we are warned from dogmatism. It cannot be 

 an easy question when we find Spencer on one side and Weismann 

 on the other, Haeckel on one side and Ray Lankester on the 

 other, Turner on one side and His on the other, and so on. 



Herbert Spencer was so convinced that he went the length 

 of writing : " Close contemplation of the facts impresses me 

 more strongly than ever with the two alternatives — either there 



