HANCOCK OX THE ANATOMY OF DIBRAXCllI LTE CEPHALOPODA. 481 



developments of the passages connecting the genital with the renal 

 chamber. 



As tlit* glandular appendages of the venaa cava* are now generally 

 acknowledged to be of a renal nature, the office of the chamber con- 

 taining them is. apparently, to receive the urine as it la secreted, and 

 then to expel it through the nipple-shaped orifices situated in the 

 branchial chamber. And the genital, which we have swu communicates 

 with the renal chamber, may be looked upon as an extension of the 

 latter; the same membrane undoubtedly forming the walls of both 

 chambers. In the renal chamber proper this membrane is iii part 

 specialized, forming the glandular appendages attached to the \ena- 

 cavffl, the blood channels themselves only supplying the vessels that 

 permeate these organs. The effete, nitrogenous and more solid 

 matters of the urine are probably eliminated by these glandular appen- 

 dages, which take upon themselves the function of the urinary tu- 

 bules of the kidneys of the higher animals ; while the other great 

 chamber, the genital, receives the fluid, perhaps little more than 

 water, that may be supposed to flow from the arterial capillaries of 

 the various organs placed within it. Assuming this to be the case, 

 then this chamber will be related functionally to these capillaries as 

 the capsule of the malphigian tuft is to the capillaries of the tuffc 

 itself. The fact appears to be, that the kidney in these, as in most 

 other mollusks, is diffused, or not fully specialized ; but nevertheless 

 here, as in the higher animals, the more solid products of the urinary 

 secretion are abstracted by the agency of secreting cells, and the 

 fluids principally by the action of mere capillary blood-vessels. 



This, then, is apparently the primary function of these so-called 

 water chambers ; but lymph may also be supposed to escape into 

 them during the act of nutrition, and mingle with their fluid con- 

 tents. This, however, is perhaps more strictly the case with regard 

 to the genital chamber, in which the fluid is probably little else than 

 lymph and pure water ; the valvular nature of the orifices connecting 

 this chamber with that containing the glandular appendages prevent- 

 ing the fluids of the latter passing into the former. The deleterious 

 urinary matters are consequently always confined to the renal cham- 

 ber proper. 



Now w r e have seen that the cardiac appendages are always bathed 

 by this fluid, both externally and internally, however the parts may 

 be modified; that their lining membrane is raised into folds and 

 wrinkles, which are clothed with minute papilla?, thus giving great 

 increase of surface ; that the papilla? are filled with granular cells, and 

 are in connexion with a highly vascular parenchyma, and that the 

 trunks of the vessels permeating this parenchyma, open into the 

 branchial hearts. It is therefore evident, from the structure of theso 

 enigmatical organs, that they arc well calculated for the selection 

 and absorption of fluid matters. I would suggest, then, that we see 

 in these cardiac appendages an apparatus for the return to the system 

 of the extravasated lymph that may have escaped into the genital 



