42 SKXIAL OKiiANS. 



The buccal parts of a female of ,SV///V/ / //hcf-nlti/a of t In- Cape, 

 present. MM- following peculiarity: the male lias fixed the whole 

 mass ol' t lie >pcrmalophoivs on the r.rfcrmil surface of the buccal 

 membrane a thing which he has never seen in any other Sepia. 

 although he has sometimes observed that, a l'e\v spermatophores 

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

 nay, even near the base of the arms S TKKXSTIU i>, Comptes 

 Rendus, 507, 1st."); Ann. May. \. ///>/., 4 ser., xvii. '.>:>, ls7<;. 



I>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 wa> 

 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 fertili/e the 

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

 may derive some support by the consideration of the ditference 

 in habit between the swimming and creeping species, which in the 

 former may sometimes render the sexual embrace more difficult 

 than in the latter. 



Lafont, who has studied at length the fecundation of various 

 species of cephalopods in the aquarium of Arcachon. had (in 

 1868) in only a single instance noticed the spermatophores placed 

 externally upon the female, and thai was under extraordinary 

 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. lie thinks that the .mode of fecundation known as 

 hectocotyli/.ation in Argonaiita and Tremoctopus. is not very 

 positively practised in Sepia and ( hmnast -replies, nor very prob- 

 ably in Loligu and Octopus; and he concludes that, it is certain 

 (from his Observation) that in the genus Sepia, the bundles of 



