SPERMATOZOA MINGLED WITH OVA. 1G5 



veiy tlisposition of ova and spermatozoa in the same ''organ ;" 

 so that if it had not been for the positive statement of 

 Kolliker, respecting the separation of the sexes, I should 

 have conceived the point placed beyond dispute. 



At the Scilly Isles and Jersey my investigations were 

 renewed, for a long time with the discouraging and para- 

 doxical result of finding ova and nothing else. It seemed as 

 if Rapp's statement would turn out to be correct, and only 

 females were to be found. But then, whence the sperma- 

 tozoa seen at Tenby ? Whence those described by Kolliker ? 

 That the absence of spermatozoa did not, in the simpler 

 organisms, by any means imply the absence of reproduction, 

 but that females were capable of propagating, unaided, I 

 I knew well enough.* This did not answer the question 

 raised. The fact that there were sometimes spermatozoa 

 seemed beyond dispute ; Kolliker had seen them, and asserted 

 them to be as numerous as ova. The solution of the diffi- 

 culty dawned upon me when I discovered that the sperma- 

 tozoa were contained in vesicles, so like ova in the early 

 stage as to be easily mistaken for them. It is only by 

 crushing these that the spermatozoa are seen escaping. 

 Thus it became intelligible that I might have had spermatic 

 vesicles in the ovaries under observation, where I thought 

 there were only ova ; and all my females might have been 

 hermaphrodite. Unhappily this clue was detected at a period 

 when I was so deeply engrossed with the nervous system of 

 the Mollusca, that I had little time to devote to the unravel- 

 ling of the whole mystery. But I made a few direct and con- 



* See Examples in Part IV., Chap. I. 



