Page:Natural History Review (1861).djvu/487

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HANCOCK ON THE ANATOMY OF DIBRANCHIATE CEPHALOPODA.
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blood-vessels and nerves, which fold unites this viscus to the anterior extremity of the genital organ. The latter is also attached to the posterior extremity of the chamber by the same membrane in Ommaastrephes and Loligo; but in Sepia and Sepiola this extremity is free.

There are two oviducts in Ommastrephes; all the other species that I have dissected have only one, which is situated on the right side. They open through the lateral walls of the chamber, and lie apparently, between these walls and that forming the boundary of the abdomen, The male intromittent organ, which is always single, is situated on the right side, and the vas deferens communicates with the chamber by a small orifice opening through the wall of the same side.

Besides the genital outlets, there are other two. as in the Octopodidæ, which bring this chamber into communication with the venal cavity. Here, however, in the place of long, fine, duct-like tubes, there are short, wide, flattened channels, which pass from the sides of the chamber in front, and dipping downwards and forwards, between the wall of the body and that of the renal chamber, open into the latter immediately behind the nipples that communicate with the branchial chamber. These channels, which open into the renal chamber by slit-formed orifices, remind us of the manner in which the ureters open into the bladder in the higher animals.

There can be no doubt that the genital chambers in the two groups are homologous. The feet that, in both, they always contain the special genital organ—that the excretory channels of these organs always open into them in the same manner—and that they are always in communication with the renal chamber, sufficiently establishes this relationship.

The two additional, small, lateral chambers in the Octopodidæ are nothing more than enlargements on the channels of communication between the two chambers. Indeed, the chamber in the Loliginidæ differs from that in the Octopodidæ chiefly in the fact, that the former contains, in addition to the special genital organ, the stomach and cæcum; these organs, in the latter, being placed in what M. Edwards, in the "Voyage en Sicile," première partie, p. 123, designates the visceral or abdominal chamber; which in the Loliginidæ is either wholly or in part wanting. These digestive organs are therefore developed backwards, and are consequently thrust, as it were, into the genital chamber, bulging in its anterior wall, which becomes reflected over them in the manner we have seen.

The true nature of these chambers is a matter of no little interest. We have seen nothing to warrant the idea that they are directly connected with the vascular system, and certainly nothing to prove that they are for the purpose of receiving water from the exterior; but rather, on the contrary, that they form part of an apparatus for ejecting from the system the effete, nitrogenous, or urinary matters, and along with them the redundant fluids. But we must reserve