518 MR. A. HANCOCK ON THE STRUCTURE AND HOMOLOGIES OF THE 
liver. Thus we may assume that it is also distinct in those species in which it is more 
or less confounded with that viseus. In these latter it is difficult, if not impossible, to 
. follow all the ramifications of the organ as they branch over and into the substance of 
the liver; and had it not been for the aid afforded by this and the following interesting 
example, doubts might have existed as to the relation of the two organs. 
In the higher Nudibranchs the connexion of the renal chamber with the liver arises, 
apparently, from the arrangement of the vascular system, which in them is more highly 
developed than in the lower forms. In the former there are both hepatic arteries and 
veins; and these, we have seen, have a certain relation to the renal chamber. It is over 
the hepatico-branchial vein, which protrudes into the chamber, that in Doris tuberculata 
the glandular matter is accumulated; and the rich vascular network that pervades the 
walls of the organ is derived from the hepatic arteries. Hence the connexion of the two 
organs. In Bornella, which is one of the lower forms, neither the hepatic arteries nor 
veins exist; the renal gland is consequently detached from the liver, which im this 
species is found only in a rudimentary state in the visceral chamber. We have seen, 
however, that the gland overlies the viscera, and to a great extent embraces the rudi- 
mentary hepatic organ, following its ramifications even into the branchial papille, 
retaining, as it were, a lingering connexion with this viscus, though it must now derive 
its blood from that which bathes the visceral chamber. 
In Dendronotus the kidney is apparently formed on the same plan as in Bornella; but 
the details of the organ could not be made out, though the posterior trunk of the renal 
chamber was observed. 
Another distinct glandular form of the renal chamber is found in Scyllea. In a 
member of this genus from Madras, and described under the name of S. marmorata*, the 
development of this organ is very remarkable. The pericardial chamber (Pl. LVIII. 
fig. 2) presents nothing uncommon ; the pyriform vesicle, however, opens into it further 
forward than usual, on the right side, immediately in front of the auricle, and, passing 
downwards, has its lower or tapering extremivy united to a tube which lies on the upper 
suriacê of the rectum (Pl. LVIII. fig. 1). This tube passes to the right side, and soon 
terminates in the minute opening associated with the anal nipple (fig. 6). The other or 
inner extremity of the tube bifurcates immediately to the left of the vesicle, one branch 
turning forward, the other backward. The former passes under the intestine, giving off 
branches as it goes, to the under side of that tube, to the gizzard, and to the anterior 
ovarian mass; it then branches over the dorsal aspect of the stomach, and sends a branch 
= woe the reproductive organs. All these branches terminate in blind sacs, and lie 
cud in the cellular tissue in connexion with the various organs; the branch, however, 
hat goes to the ovarian mass is more intimately attached to the surface of the orga” 
and forms minute and beautiful dendritie ramifications over it. The posterior branch of 
the tube passes backwards along the dorsal surface of the liver, towards the right side, 
and distributes offsets to the two posterior ovarian masses, and sends numerous dendritic 
ramuscules to both the upper and under surface of the liver. The hepatic ramuscules 
lie loosely attached to the surface of the organ, and all their twigs end in blind sacs like 
* Trans. Zool. Soc. vol. v. p. 136. 
