14 An Examination of Weisniannism. 



seductive fallacy of attributing the origin of sexual 

 propagation to the agency of natural selection. Great 

 as the benefit of this newer mode of propagation must 

 have been to the species presenting it. the benefit 

 cannot have been conferred by natural selection, 

 seeing that the benefit arose from the fact of the 

 new method furnishing material to the operation 

 of natural selection, and therefore constituting the 

 condition to the agency of natural selection having 

 been called into existence at all. Or, in other 

 words, we cannot attribute to natural selection 

 the origin of sexual reproduction without involv- 

 ing ourselves in the absurdity of supposing natural 

 selection to have originated the conditions of its 

 own activity '. What the causes may have been 



1 Since this chapter was written and sent as a contribution to the 

 Contemporary Revieiu. Professor Weismann has published in Nature 

 ,Feb. 6, 1S90) an elaborate answer to a criticism of his theory by 

 Professor Vines (Oct. 24, 18S9). In the course of this answer Professor 

 Weismann says that he dots attribute the origin of sexual reproduction 

 to natural selection. This directly contradicts what he says in his 

 Essays ; and, for the reasons given in the text, appears to me an illogical 

 departure from his previously logical attitude. I herewith append 

 quotations, in order to reveal the contradiction. 



" But when I maintain that the meaning of sexual reproduction is to 

 render possible the transformation of the higher organisms by means of 

 natural selection, such a statement is not equivalent to the assertion that 

 sexual reproduction originally came into existence in order to achieve 

 this end. The effects which are now produced by sexual reproduction 

 did not constitute the causes which led to its first appearance. Sexual 

 reproduction came into existence before it could lead to hereditary 

 individual variability [i. e., to the possibility of natural selection]. Its 

 first appearance must, therefore, have had some other cause [than 

 natural selection] ; but the nature of this cause can hardly be determined 

 with any degree of certainty or precision from the facts with which we 

 are at present acquainted." — Essay on the Significance of Sexual Re- 

 production in the Theory of Xatural Selection. English Translation, 



pp. 2^1-jSj. 



" I am still of opinion that the origin of sexual reproduction depends 



