SPERMATOZOA MINGLED WITH OVA. 1G7 



miilate on one part of the septum, and the ova on another 

 part of the same septum ; or different septa may bear diffe- 

 rent kinds of cells. 



3d. There may be others — and this has its parallel in 

 other Polypes, in Crustacea, and in Insects — which produce 

 nothing hut ova ; and these ova may develop into embryos, 

 without the concourse of spermatozoa at all. 



•4th. Or finally, the slight indication of the separation of 

 sex, which is presented when one side of the septum, or one 

 of tlie septa, develops only one kind of cell, may be further 

 carried out in some species, and in thcTii the complete sepa- 

 ration of sexes takes place. 



Of these four possible forms, I have positive observation 

 only of the first, and am strongly inclined to believe in the 

 third ; there is, however, nothing at all improbable in the 

 second and fourth, and either, or both, may be ascertained 

 by careful investigation, which would rectify or confirm the 

 observations of Kolliker and Hollard. But it must not be 

 forgotten that, although a single case of distinct separation — 

 a single Actinia fomid bearing spermatozoa only on all its 

 septa — would sufiice to establish the truth of the fourth pro- 

 position ; yet for this to be established, the inquirer must 

 be rigorously certain that all the septa bear the spermatozoa, 

 the ova being everywhere absent ; and even then no amount 

 of such evidence will invalidate the fact announced in the 

 first proposition, that in some cases the ova and spermatozoa 

 are miugled ; a fact I have quite recently discovered also in 

 the fresh- water Polype. Whether Actinia) are, or are not, in 

 general, of separate sexes — and I think they are never or 



