374 W. B. Scott — Valuations and Mutations. 



that process, such as is maintained by Weismann and his fol- 

 lowers. The difficulties involved in this theory are very well 

 brought out by Bateson who says that it " asks us to abrogate 

 reason." The particular value which attaches to the facts of 

 palaeontology in this connection, is that they give us what we 

 have every reason to believe are the actual steps of descent in 

 the history of a genus or species. On the other hand, no one 

 has ever observed the birth of a new species through the grad- 

 ual accumulation of individual differences. How these appar- 

 ently contradictory classes of evidence are to be reconciled 

 must be determined by wider and fuller knowledge, but the 

 way to obtain such knowledge is not to dogmatically enunciate 

 a theory and then refuse to consider the facts which do not 

 favor it. 



Another very obvious objection to the mode of evolution 

 here suggested lies in its apparent appeal to a mystical direct- 

 ing force which makes for differentiation or simplification, as the 

 case may be, the nature of which we can hardly even hope to 

 learn. Such mysterious forces are to be admitted only when 

 there is absolutely no escape from them. This notion of a 

 directing factor in evolution may be altogether illusory and yet 

 it is difficult to shake it off. Jt is continually reappearing in 

 one form or another in the writings of those who do not ex- 

 plicitly acknowledge it and are perhaps hardly conscious that 

 their views imply it. The later theories of "Weismann necessi- 

 tate its assumption in some shape. But this force may after 

 all be only the expression of some general law which has not yet- 

 been formulated, but if it be real, we shall not advance our 

 science by shutting our eyes to it. We have then to endeavor 

 to learn the facts of nature and having learned them, attempt 

 to explain them. Many current explanations have been de- 

 vised to account for assumed facts and these we can afford to 

 neglect. 



In making the suggestions contained in this paper, I am very 

 far from desiring to propound a new theory of evolution or to 

 dogmatically insist upon the interpretations of the facts as 

 given. These interpretations profess to be nothing but sug- 

 gestions which are not even novel, but they are derived from 

 well established facts, which indicate in the plainest manner that 

 we can no longer assume as a fundamental and self-evident 

 truth, that individual variations are the material from which 

 new species are constructed. 



Geological Museum, Princeton College, Sept. 3, 1894. 



