202 An Examination of Weismannism. 



by appealing to the fact of a previous sire sometimes affecting 

 the progeny of a subsequent one. The case, however, is widely 

 different if we turn from animals to plants, thus. 



The advantage which any theory of gemmules seeks to gain 

 over the theory of germ-plasm by an appeal to the fact in ques- 

 tion, consists in supposing that the influence of the previous sire 

 is exercised in the first instance on the somatic cells of the female. 

 For this would prove that the germinal elements of the male are 

 capable of communicating their hereditary qualities, not only 

 by mixing with the germinal elements of the female (as in 

 ordinary fertilization) but also by direct contact with the general 

 tissues of the female. And this again would prove that the 

 fundamental postulate of the theory of germ-plasm is erroneous 

 — i.e., the postulate of the continuity of germ-plasm, or of its 

 perpetual restriction to a " sphere " of its own. This, as all who 

 are acquainted with the literature of the subject will at once 

 perceive, would be a serious blow to the whole Weismannian 

 system. But, as we have seen, the current Lamarckian inter- 

 pretation of the fact in question involves the supposition of 

 a physiological machinery so inconceivably complex that instead 

 of serving to corroborate the theory of gemmules (or of physio- 

 logical units) it would go to render that theory incredible a . 



1 As already indicated, I cannot gather from his remarks on the subject 

 which, if any, of the alternative interpretations of the phenomena that 

 we are considering Mr. Spencer adopts. From the following sentences 

 it would appear that he assigns yet a third interpretation, and this as the 

 only possible one. For he says of these phenomena: "They prove 

 that while the reproductive cells multiply and arrange themselves 

 dining the evolution of the embryo, some of their germ-plasm passes 

 into the mass of somatic cells constituting the parental body, and 

 becomes a permanent component of it. Further, they necessitate the 

 inference that this introduced germ-plasm, everywhere diffused, is some 

 of it included in the reproductive cells subsequently formed " [Contem- 

 porary Revieiv, March, p. 452}. This appears to mean that the 

 influence of a previous sire can only be explained by supposing that the 

 developing embryo inoculates the somatic tissues of its mother with 

 hereditary material derived from its father, and that the maternal tissue 

 afterwards reflect some of this material (or its influence) to ihe still 

 unripe ovarian ova. If this be the hypothesis intended, it seems to me 

 more complex than any of the three which I have suggested. But, be 

 this as it may, we certainly cannot agree that such an hypothesis 



