INADEQUACY OP NATURAL SELECTION, ETC. 651 



dozen ; so that a few replies and rejoinders produce an un- 

 manageable population of issues, old and new, which end in 

 being a nuisance to everybody. Remembering this, I shall re- 

 frain from dealing with all the points of Professor Weismann's 

 answer. I must limit myself to a part ; and that there may be 

 no suspicion of a selection convenient to myself, I will take those 

 contained in his first article. 



Before dealing with his special arguments, let me say some- 

 thing about the general mode of argument which Professor Weis- 

 mann adopts. 



The title of his article is "The All-Sufficiency of Natural 

 Selection." * Very soon, however, as on p. 322, we come to the 

 admission, which he has himself italicised, " that it is really very 

 difficult to imagine this process of natural selection in its details; and 

 to this day it is impossible to demonstrate it in any one point." 

 Elsewhere, as on pp. 327 and 336 a propos of other cases, there 

 are like admissions. But now if the sufficiency of an assigned 

 cause cannot in any case be demonstrated, and if it is " really 

 very difficult to imagine " in what way it has produced its al- 

 leged effects, what becomes of the "all-sufficiency" of the cause ? 

 How can its all-sufficiency be alleged when its action can neither 

 be demonstrated nor easily imagined ? Evidently to fit Professor 

 Weismann's argument the title of the article should have been 

 " The Doubtful Sufficiency of Natural Selection." 



Observe, again, how entirely opposite are the ways in which 

 he treats his own interpretation and the antagonist interpreta- 

 tion. He takes the problem presented by certain beautifully 

 adapted structures on the anterior legs of " very many insects," 

 which they use for cleansing their antennae. These, he argues, 

 cannot have resulted from the inheritance of acquired characters ; 

 since any supposed changes produced by function would be 

 changes in the chitinous exo-skeleton, which, being a dead sub- 

 stance, cannot have had its changes transmitted. He then pro- 

 ceeds, very candidly, to point out the extreme difficulties which 

 lie in the way of supposing these structures to have resulted from 

 natural selection : admitting that an opponent might " say that 

 it was absurd " to assume that the successive small variations im- 

 plied were severally life-saving in their effects. Nevertheless, he 

 holds it unquestionable that natural selection has been the cause. 

 See then the difference. The supposition that the apparatus has 

 been produced by the inheritance of acquired characters is 

 rejected because it presents insuperable difficulties. But the 

 supposition that the apparatus has been produced by natural 

 selection is accepted, though it presents insuperable difficulties. 



* Contemporary Review, September, 1893. 



