26 INITIATIVE IN EVOLUTION 



present in the germ. It is not a question of Nature or Nurture, but 

 perhaps may be found to be a study of Nature and Nurture. It is 

 not a question of Mendelian analysis, nor as to the distribution 

 of either mutations on the one hand, nor of minute fluctuating 

 variations on the other. The problems are therefore limited 

 in scope and ambition, and are none the worse for that, as being 

 better open to correction or support. 



The Problems Considered. 



It seems but natural to most persons who contemplate with 

 any care the ever-changing and progressive drama of life in plants 

 and animals that unquestionably the dramatis personce by their 

 individual response to the environments and exercise of their 

 functions must contribute a share, however small, to their offspring. 

 When first this view presents itself to their minds they resent as 

 " unnatural " any other possibility. But, alas ! they find that 

 such a conclusion is not permitted in those regions where alone 

 the white light of science shines. Here the writ of a priori does 

 not run. The spirit of inquiry makes its challenge to every pre- 

 supposition and every assertion in its province — even those of 

 current science. I have shown that this particular assumption of 

 the natural man was firmly challenged by Weismann, who was not 

 the first, but the greatest, biologist to teach that modifications are 

 not transmitted. Accordingly, agreeable and convenient as it 

 would be to assume the Lamarckian hypothesis as a working one, 

 it needs in the present day to be supported by evidence before this 

 can be allowed. Facts, then, against Weismann 's dogma are 

 demanded and of such a kind as will satisfy so powerful an advocate 

 of his own views. In passing it may be remarked again that there 

 is nothing so misleading as facts, except statistics, and for both 

 sides to bear in mind the warning of a French writer that in such 

 inquiries as this we should be careful lest we find the facts for 

 which we are looking. 



To meet the conditions laid down in Professor Thomson's 

 Canon I propose to describe certain phenomena which are adduced 

 as instances of modifications in certain mammals whose structure 

 and mode of life are intimately known, and whose ancestry is little 

 in dispute. 1 The most convincing of these lines of evidence are 

 those which are shown to be outside the range of any form of 

 selection, as well as the distributional factors of Mendel and 



1 With the exception perhaps of the highest of all, for since the publica- 

 tion of Prof. Woods Jones' Arboreal Man the question " Who is Man ? " has 

 received a new answer. 



