Weismannism tip to date (1893). I2 9 



determinant in the soma as to cause it to impart an 

 abnormal colour to the spot when formed, a similar 

 change is likely to be simultaneously effected in the 

 corresponding determinants which are lying dormant 

 in the germ-plasm. Therefore, when the latter become 

 active in the ontogeny of the next generation, they 

 will produce spots presenting the same variations as 

 those of the preceding generation. Obviously, how- 

 ever, there would not be here any transmission of 

 acquired characters. The change would be " special- 

 ized," but not " representative." 



No doubt we have here a sufficiently ingenious 

 method of circumventing an awkward class of facts. 

 But I should like to make two observations with 

 regard to it. 



In the first place, the suggestion is highly specu- 

 lative, and has been advanced solely for the sake of 

 saving the theory of germ-plasm. There are no facts 

 adduced in its favour, and it could scarcely be enter- 

 tained as in the least degree probable by any one 

 who has not already accepted the theory in question. 

 Hence, unless we are to embark on a course of 

 circular reasoning, we must refuse to accept the 

 explanation of hereditary climatic variation now 

 offered, until it shall have been fully corroborated by 

 the experimental enquiry to which Weismann says he 

 is now submitting it. 



My second observation is, that the suggestion is 

 not new ; but appears to have been derived from 

 Professor Weismann's recent study of Mr. Galton's 

 Theory of Heredity. At all events, the suggestion is 

 there presented with sufficient lucidity, thus : — 



It is said that the structure of an animal changes when he is 



K 



