Characters, Hereditary and Acquired. 95 



appear to have exclusive reference to this peculiar 

 state of matters. Possibly, however, Perrier might 

 be able to meet each of these particular instincts, 

 by showing how they could have arisen out of 

 simpler beginnings, prior to the separation of the two 

 functions in question. There is no space to consider 

 such possibilities in detail ; but, until this shall 

 have been done, I do not think we are entitled to 

 conclude that the phenomena of instinct as presented 

 by neuter insects are demonstrably incompatible with 

 the doctrines of Lamarck — or, that these phenomena 

 are available as a logical proof of the unassisted 

 agency of natural selection in the case of instincts 

 in general ^ 



(B.) 



Inherited Effects of Use and of Disuse. 



There is no doubt that Darwin everywhere attaches 

 great weight to this line of evidence. Nevertheless, 

 in my opinion, there is equally little doubt that, 

 taken by itself, it is of immeasurably less weight than 

 Darwin supposed. Indeed, I quite agree with Weis- 

 mann that the whole of this line of evidence is 

 practically worthless ; and for the following reasons. 



The evidence on which Darwin relied to prove 



' \See H. Spencer, The Inadequacy of Natural Selection, A Rejoinder 

 to Professor Weismann, Contemp. Kev. 1893; and IVeismannism once 

 more,lhid.Oz\. 1894 ; Weismann, The All-sufficiency of Natural Selection, 

 Ibid. 1893; anil The Effect of External hifluences upon Development, 

 "Romanes Lecture" 1894: also Neuter Insects and Lamarckism, 

 W. Piatt Ball, Natural Science, Feb. 1894, and Neuter Insects and 

 Darwinism, J. T. Cunnmgham, Ibid. April 1894. C. LI. M.] 



