ORGANIC EVOLUTION — THE FACTORS 129 



in reply, suggests that it is possible that the immature 

 ova are sometimes (e.g. in the cases cited) directly 

 infected by the germ-plasm of the first male, a not 

 improbable explanation, since we know that the sperma- 

 tozoa do actually reach the ovaries, as is proved by 

 many recorded cases of ovarian and abdominal foeta- 

 tion. Mr. Spencer scouts his suggestion, and asks — 



" Why in such a 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 ? " (p. 68). 



Professor Romanes has, however, already by antici- 

 pation answered the objection by opining — 



"That the life of ids" (i.e. groups of biaphors) "is 

 not commensurate with that of their contained sperma- 

 tozoa. After the latter have perished and disintegrated, 

 their ids may escape in thousands of millions, bathing 

 in a dormant state the whole surfaces of both ovaries. 

 And if so, it is conceivable that when subsequent ova 

 mature, i. e. come to the surface of their ovaries and 

 rupture their follicles, these dormant ids adhere to their 

 porous walls through which they may pass." 



And therefore since the whole of a spermatozoon of 

 a previous sire does not enter the ovum it is not 

 entirely fertilized, and all his traits are not transmitted ; 

 but as only part of his spermatozoon enters, the ovum 

 is only partially fertilized, and his traits are only in 

 part transmitted. Mr. Spencer objects "that the 

 surface of a mammalian ovarium is not a spermatheca " 

 (p. 68), but when he speaks of " a foreign germ-plasm 

 permeating the organism," does he not himself seem to 

 consider the tissues in general of the female as a 



K 



