198 Messrs. Hancock and Embleton on the Anatomy of Kolis. 
hepatic artery is wanting, but the fact of the liver being minutely 
divided among the branchial papillee, and the divisions being thus 
placed in contact with aérated blood, explains this hiatus and ne- 
cessitates it. The auricle receives three principal venous trunks, 
each of which is made up of several branches from the skin ante- 
riorly and posteriorly. These trunks have been called branchio- 
cardiac by M. Milne-Edwards and his followers, under the convie- 
tion that the whole of the blood passes to the heart from the 
branchial papillz by them. We find nothing in Kolis to favour the 
opinion that the whole of the blood is conducted by afferent vessels 
from the body or intervisceral lacune direct to the branchie, 
and thence exclusively by efferent vessels to the auricle. We see 
that the network of lacunze in the thickness of the skin receives 
the blood from the interior of the body, and allows it to flow 
freely therein in all directions ; part of it doubtless passes to the 
branchial papille, but part also must go at once along the veins 
to the auricular part of the heart. In other words, the veins draw 
their blood from the sinuses or lacune of the skin, and this sue- 
tion, so to speak, attracts the vital fluid at one and the same 
time from the branchial papille and the lacune of the body, so 
that the veins, instead of being merely branchio-cardiae, are really 
both systemic and pulmonary together. We have likewise pointed 
out small veins going from one of the viscera, the ovarium, into 
the skin at the side of the body, and even a small vessel of 
similar character going from the ovarium into the posterior me- 
dian trunk-vein ; the latter of course are systemic veins. Again, 
we find corroboration of this view of the parts in Eolis if we 
look to Doris: here the auricle receives three branches, one from 
each side, and one from behind as in Holis; this last branch in 
Doris is made up of veinlets from the respiratory organs alone, 
and hence may properly be called pulmonary or branchio-cardiac; 
the two lateral branches come not from the special respiratory 
organ at all, but directly from the skin. Now although the skin 
in Doris may have in some measure a function like that of the 
Eolidide, it must from its peculiar nature perform that function 
in a most imperfect manner ; hence we ought to look upon these 
lateral venous trunks in a corresponding inverse ratio as systemic 
veins. Thus both in Doris and in Eolis the blood enters the 
auricle in a state of only partial aération, one portion reaching it 
from the respiratory organ, and another from the general system. 
In the Crustacea the blood in the great dorsal smus is in the 
same state, a fact that John Hunter had long ago ascertained, 
and Professor Owen has more recently confirmed. Here surely 
there is not that degradation implied in the idea of Phleben- 
terism ; and according to M. Milne-Edwards’ own showing, the 
