206 An Examination of Weismannism. 



There is one other passage in Dr. Romanes' criticism — that 

 concerning the influence of a previous sire on progeny — which 

 calls for comment. He sets down what he supposes Weismann 

 will say in response to my argument. " First, he may question 

 the fact." Well, after the additional evidence given above, 

 I think he is not likely to do that ; unless, indeed, it be that 

 along with readiness to base conclusions on things " it is easy 

 to imagine " there goes reluctance to accept testimony which it 

 is difficult to doubt. Second, he is supposed to reply that " the 

 germ-plasm of the first sire has in some way or another become 

 partly commingled with that of the immature ova " ; and 

 Dr. Romanes goes on to describe how there may be millions 

 of spermatozoa and " thousands of millions " of their contained 

 " ids " around the ovaries, to which these secondary effects are 

 due. But, on the one hand, he does not explain why in such 

 case each subsequent ovum, as it becomes matured, is not 

 fertilized by the sperm-cells present, or their contained germ- 

 plasm, rendering all subsequent fecundations needless ; and, on 

 the other hand, he does not explain why, if this does not happen, 

 the potency of this remaining germ-plasm is nevertheless such 

 as to affect not only the next succeeding offspring, but all 

 subsequent offspring. The irreconcilability of these two impli- 

 cations would, I think, sufficiently dispose of the supposition, 

 even had we not daily multitudinous proof that the surface of a 

 mammalian ovarium is not a sperm-atheca. The third difficulty 

 Dr. Romanes urges is the inconceivability of the process by 

 which the germ-plasm of a preceding male parent affects the 

 constitution of the female and her subsequent offspring. In 

 response, I have to ask why he piles up a mountain of 

 difficulties based on the assumption that Mr. Darwin's 

 explanation of heredity by " Pangenesis " is the only available 

 explanation preceding that of Weismann ? and why he presents 

 these difficulties to me more especially, deliberately ignoring 

 my own hypothesis of physiological units ? It cannot be that 

 he is ignorant of this hypothesis, since the work in which it is 

 variously set forth ("Principles of Biology," §§ 66-97) is one 

 with which he is well acquainted : witness his " Scientific 

 Evidences of Organic Evolution " ; and he has had recent 

 reminders of it in Weismann's " Germ-plasm," where it is 



