AND THE MALES OF CERTAIN CEPHALOPODS. 125 



tubercles in its interior, which are everted during copulation), 

 which is continued into the penis, are contained. M. Kolliker 

 describes these tuberculosities as little conical spines. 



Besides the Hectocotylus Tremoctopodis, M. Kolliker describes 

 and figures that of the Argonaut, which is distinguished from 

 the former by the absence of branchiae, of a sac-like abdomen, 

 of a free penis, and by the presence of a filiform appendage 

 which passes from the anterior extremity of its body. At the 

 base of this appendage two triangular membranous lobes are 

 placed. 



The anatomical structure of this animal differs only in the 

 structure of the filiform appendage and in that of the sexual 

 organs. The filiform appendage is the continuation of the mus- 

 cular tube forming the axis of the body. The testicular capsule 

 is elongated and lined with pig rent-cells, which are probably 

 contractile. The testicle itself is formed by a spermatic thread 

 coiled up, and surrounded by a structureless membranous enve- 

 lope. The efferent duct leads into a silvery cylindrical tube, 

 which is probably the penis, and which is certainly of a mus- 

 cular nature. 



M. Kolliker adds to this description of the Hectocotyli a long 

 dissertation, in which he sets forth the opinions of his prede- 

 cessors, as well as his own, the latter amounting to this, that the 

 Hectocotyli are the stunted males of certain speciesof Cephalopoda. 

 " There is no need (he says) for any lengthy evidence that the 

 Hectocotyli are independent animals. He who has not seen, as 

 MM. Laurillard, Delle Chiaje, and I have done, their lively, 

 independent, and continued movements, will not take them 

 for portions of Cephalopods, and still less for spermatophora, 

 if he considers their complicated organization, and if he calls 

 to mind that they have a heart with vessels, branchiae, nerves, 

 and such well-developed generative organs." In the face of this 

 positive assertion of M. Kolliker, we shall undertake to prove 

 that the Hectocotyli are, however, nothing more than detached 

 arms of Cephalopods, merely organized in a special manner. 



After having shown that we were still unacquainted with the 

 male of the Argonaut and with that of the Tremoctopus, M. Kol- 

 liker brings forward, first, the resemblance of structure between 

 the Hectocotyli and the Cephalopoda ; he finds that the suckers, 



