Weismannism tip to date (1893). 143 



effected. But, as regards this question, I retain my 

 original opinion. For, while I can see no theoretical 

 difficulty in supposing that " the carriers of heredity," 

 when set free by the disintegration of their containing 

 spermatozoa, may reach the unripe ova while still 

 embedded in the depths of the ovary, I do see a 

 difficulty, amounting almost to a physiological im- 

 possibility, in supposing that a whole spermatozoon 

 can perform such a feat. From all that we know 

 about the powers and functions of spermatozoa in the 

 vertebrata, it appears simply absurd to imagine that 

 these bodies are able to penetrate the dense coating of 

 an ovary, and then delve their way through the stroma. 

 There is, indeed, a remarkable investigation which 

 was published a year or two ago by Mr. Whitman 1 

 which appears to prove that in certain leeches the male 

 injects his seminal fluid into any part of the body of 

 the female, and that the spermatozoa then reach the 

 ova by wandering about her general tissues until some 

 of them happen to hit upon her ovary. But in this 

 case the spermatozoa are specially adapted to perform 

 such acts of penetration — being spear-like bodies 

 provided with a sharp point. Hence, if Weismann 

 should quote this instance, it would not tend to 

 support his view, seeing that the spermatozoa of 

 mammals do not exhibit any such specializations of 

 structure ; and therefore, before any one of them can 

 effect fertilization, must w T ait for the ovum to mature, 

 reach the surface of the ovary, and rupture its follicle. 

 But, as already observed, it does not signify, so 

 far as we are here concerned with the matter, in what 

 precise manner the telegonous influence may be 



1 Morph. Journal, vol. ii. 



