QUARTERLY CHRONICLE. 93 
FRANCE.—Comptes Rendus.—In the number for December 
18th we observe a paper, by Dr. Lacaze-Duthiers, ‘‘ On the 
Circulation of the Inferior Animals’? The author observes 
that it is impossible to take up any ordinary mollusc and 
examine it without observing that a fluid exudes from its 
body in sufficient quantity generally to thoroughly wet the 
hands of the observer. The answers to the questions as to 
what is this liquid, whence it comes, and how it escapes, are 
the object of the present memoir. There is no doubt that a 
great number of the lower animals deprive themselves of the 
liquids of their economy by voluntary bleeding; but this does 
not take place in the same way in all groups. With regard 
to the Mollusca, positive facts demonstrate beyond doubt that 
there is a communication between the circulatory apparatus 
and the external world. It has been shown by MM. Langer 
and Gegenbauer in Pteropods and Lamellibranchs, and by 
Dr. Duthiers himself in the Gasteropoda. In the Thetys 
leporina of the Mediterranean, between each pair of branchiz 
(numbering from fourteen to twenty on each side) which it 
carries on its back, is an oval fossa, containing a little pro- 
jecting body -pierced by an orifice. An injection carefully 
introduced at this orifice passes into the veinous system, or, 
if merely made to play on it, will be rapidly taken in. There 
are thus, then, in the Thetys from twenty-eight to forty ori- 
fices by which water can be introduced into the circulatory 
system or the blood be expelled. It is not, therefore, sur- 
prising that when one handles this animal the hand becomes 
inundated with fluid. The orifices are here provided with 
two nerves, regulating sphincter muscles. In some cases the 
contraction of a mollusc may be so violent as to cause the 
blood to rupture the tissues and escape without the use of the 
normal exit. In Dentalium and Pleurobranchus M. Duthiers 
has described a valve and two muscles which regulate the 
passage of the liquid. In the Gephyrians (Sipunculus, &c.) 
M. Duthiers compares the “ perivisceral fluid” to the blood of 
the Mollusca, since it can be expelled by the generative ori- 
fices and by the canals of the renal glands. We may add, 
that in the Oligocheta (earthworm, &c.) a constant commu- 
nication exists between the.perivisceral fluid and the exterior, 
both by the segmental organs and by the dorsal pores disco- 
vered by Mr. Busk, and figured in Mr. Lankester’s paper on 
the earthworm (‘ Quart. Journ. Micr. Science, Jan., 1865). 
In the cclenterate zoophytes the author considers the 
mouth itself as representing these orifices of exudation. In 
the solitary forms, however (Actinia, &c.), we have the tips 
of the tentacles perforated for the egress of the perivisceral 
