42 SEXIAL ORGAN!>. 



The buccal parts of a female of Sepia tuherculata of the Cape, 

 present the following peculiarity : the male has fixed the whole 

 mass of the si)ermatophores on the external surface of the buccal 

 membrane — a thing which he has never seen in any other 8epia, 

 although he has sometimes observed that a few spermatophores 

 had separated from the others and fixed on the external surface, 

 nay, even near the base of the arms — Steenstrup, Gomptes 

 Bendus, 567, 1815 ; Ann. Mag. N. Hint., 4 ser., xvii, 93, lS7fi. 



T)r, Bert, in the course of his researches upon the physiology 

 of Sepia, remarked two individuals in coitu, and upon separating 

 them discovered that the hectocotylized arm of the male was 

 thrust within its own mantle opening, instead of, as he expected, 

 that of the female. Is it not possible that in some genera at 

 least, of the decapods, the want of a covered passage through 

 the hectocotylized arm for the transmission of the spermato- 

 phores, is remedied by the mechanical action of the arm itself 

 in transmitting them from the mantle pouch and fixing them to 

 the interior face of the buccal membrane of the female, where 

 they may remain until by their bursting (perhaps assisted by 

 compression of the membrane) the innumerable sperms are dif- 

 fused through the water, and thus gain access to and fertilize the 

 ova. I put this forward with some hesitation, as a theory Avhich 

 may derive some support by the consideration of the difference 

 in habit between the swimming and creeping si)ecies, which in the 

 former may sometimes render the sexual embrace more ditficult 

 than in the latter. 



Lafont, who has studied at length the fecundatiuu of various 

 species of cephalopods in the acpiarium of Arcachon, had (in 

 1868) in only a single instance noticed the spermatophores placed 

 externally upon the female, and that was under exti-aordinary 

 circumstances; the individuals belonged to different species of 

 Sepia, and the opposition of the female to the sexual union was 

 manifest, and resulted in the infliction of injuries from which 

 both died. He thinks that the mode of fecundation known as 

 hectocotylization in Argonauta and Tremoctoiius, is not ver^"^ 

 positively practised in Sej)ia and Ommastrephes, nor ver}'^ prob- 

 ably in Loligo and Octopus; and he concludes that it is certain 

 (from his observation) tliat in the genus Sepia the bundles of 



