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64 A N A T O M Y 01' THE S E P I A L O L I G O.
fixed on cach fide to the inner part of the loofe mufcular flieath, between it and
the abdominal bowels. .
Each of thefe gills is provided with a heart for drivang the blood tlirough it;
in confequence, perhaps, of the diihincc from each other at which the gills are
placed. Another fingularity occurs, that the branchial or pulmonary veins, or
veins returning the blood from tiie gills, inftead of joining together to form the
aorta, as in fiihes, run into dlffereat fides of a mufcular fac or ventricle, fliaped
like an egg; from the two ends of which the aortas are fent out.
Hence there are in this animal three hearts or organs for reiloring momentum
to the blood: of which, with their veflcls, I iliall now give a more particular
defcription, beginning with the venas cavas.
The anterior vena cava {/:), R , is placed under the liver, contiguous to the
reflum-^ and receives branches from the arms and the head S, the liver T , the
ovarium, the fiomach, inteflines, and from fome fliare of the upper and back
part of the body V V.
Near to the back part of the liver,' the anterior vena cava divides into two
equal branches W W , which meet with two large veins X X from the under and
poilerior part of the animal, and which are analogous to the pofterior venas
cavffi of fiilaes. The cavse, where tliey meet, have a degree of reticular work, or
cornese columna: et fovese, on their inner fide ; and from their meeting, facs Y Y,
of the fame fize and ilrapc on right and left fides, are produced; or on cach fide
an oblong bag is formed, analogous to our right auricle ; and both bags are inclofed
in one large membranous fac or pericardium. To each of the auricles a
ventricle ZZ is cormected, of the ordinary conical iliape, and inclofed in its
proper membranous bag or pericardium.
From each ventricle an aitery aaaa is fent out to the correfponding gill.
When the vcntricle of the heart and this artery are cut open, the communication
between the auricle and ventricle is found to be of a round fliape, fig. i.b ;
and a rifing ñeíhy edge <?, on the outer fi'd'e of it between it and the artery, feems
to ferve the office of a valve.
A t the beginning of the artery a tliree valves d are formed, rcfcmbling the
valves in fiilies.
The artciy of the gill, or pulmonary artery iz«, fig. i. is remarkably large
in proportion to its correfponding vein ee.
The pulmonary veins terminate near the middle of a thick fleilry íac g, which
produces a conical end both on the fore and back parts, or refembles two cones
joined together by their bafes. From the fore end of this conical ventricle
a large arteiy ¿ is produced, which may be called the anterior or afcending
aorta.
The artery from the back end of the ventricle or poilerior aorta i, is confiderably
fmaller than the anterior.
When this ventricle and thefe two arteries are flit open (fee fig. 2.), a pair of
mcm-
(Í) S« Tabic xi.r.
A N A T O M Y OF THE S E P I A L O L I G 0.
membranous valves, like thofe at the termination of our thoracic duel, aré
found at the termination of each of the veins of the gills
A t the beginning of both aortae there are membranous valves //.
The anterior aorta fupplies the arms, the head, the fiver, the mufcles above
the back-bone m, the alimentary canal (fee fig. i.«), and the organs of urine
and generation.
The poilerior aorta gives fmall branches to the two pulmonary hearts 0 0, and
to the ink-bag^, and then runs towards the tail and under part of the outer
mufcular iheath fupported by a double membrane r, which fixes the abdominal
vifcera to that iheath.
From all the branches of the aorta the blood returns direclly by the two
ven« cavae to the pulmonary hearts ; for there is no vena portarum as in fillies.
The eyes (fee fig.3. i,r,) are very large, and have broad eye-lids. The
vitreous humour has the ufual appearance: but the cryftalline / is inclofed behind
in a fofter fubfl:ance or coat u ; and before is glued by a hard plate to the
cornea, widaoufthe intervention of the iris or aqueous humour^ So that the
cryilalline lens confifi:s of three different parts or pieces.
Between the eyes a foft fubilance is found, which 1 fuppofe to be the brain v,
and which is placed immediately above the cefophagus G G. To it two large
lobes X fome\ lat firmer than the middle pait, are clofely conneded, whether
cerebral or mufcular parts I am uncert^n and from or through them the '
optic nerves run to the bottom of the eye.
The middle part of the brain is connefted by crura to two lobes 22, placed
lower and farther back, which feem to be analogous to our cerebellum. The
left lobe is left bare at z.
From the latter a white thread, larger than a briille, runs backwards, which
has fome diftant refemblance to the fpinal marrow, but from the fmallnefs of it,
there is a difficulty in determining its nature •w-kh certainty or much probability.
Near to the fubilance which I fuppofe to be the brain, I found a fmall ilone
which refembles the ilone in the ear of fiíhes(¿); but I have not lately met with
one of thefe animals in order to profecute this obfervation.
<i) Tab. XLir.
C H A P .
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