288 THE CEPHALOPODA. $$ 251, 252. 
CHAPTER VII 
CIRCULATORY SYSTEM. 
§ 251. 
The circulatory system of the Cephalopoda does not appear more highly 
developed than that of the other Mollusca.” However, this subject is still 
deficient in creditable observations, and especially in those relating to the 
absence of completely-closed vessels. 
The blood is usually colorless, or of a green-bice, or violet-bice color, and 
contains, proportionably, numerous round corpuscles enclosing many gran- 
ules most of which are colorless, but with a few, scattered here and there, 
of a violet hue.” j 
§ 252. 
The Central organ of the circulation consists, with all the Cephalopoda,. 
of a simple ventricle, situated in the centre of the cavity of the body, and 
‘surrounded with a pericardium. It is round, or oblong,” and serves as an 
aortic heart. 
With Nautilus (Tetrabranchiata), this organ receives, on each side, 
two branchial veins; while with the Dibranchiata there is one vein 
only, and the heart sends off a superior and an inferior aortic trunk. The . 
mouth of the veins and the origin of the arteries are furnished with 
valves.© The Ascending aorta first sends two branches to the mantle, 
then gives off branches to the liver, to the upper portion of the digestive 
canal, to the inferior salivary glands, and to the funnel. Behind 
the cephalic cartilage it bifurcates, forming a ring embracing the 
upper extremity of the cesophagus, and from which arise two arteries for 
the ocular bulbs, eight or ten for the arms, and many small branches 
for the parts of the mouth.” The Descending aorta furnishes branches to 
1See Miine Edwards, and Valenciennes, 
Compt. rend. XX. 1845, p. 261, 750, or Froriep’s 
neue Notiz, XXXIV. p. 84, 258; also Milne 
Edwards, Ann. d. Sc. Nat. III. 1845, p. 341. 
This Jast author has also described (Ann. d. Sc. 
Nat. VIII. p. 53), the circulatory system of the 
Loligina, which is interrupted by a large sinus ; 
but he makes no mention of the aquiferous system. 
As of late there is increasing evidence for the 
opinion, that, with various invertebrate animals, 
the blood-system communicates externally at ccr- 
tain points on the body, and can therefore receive 
water into its interior, it is now important to inves- 
tigate the direct or indirect relations hetween this 
and the aquiferous system which is so widely 
spread through the Mollusks, the Worms and the 
Zoophytes. It may he that this aquiferons system, 
if it really communicates with the blood system, 
corresponds to 2 lymphatic apparatus, although it 
seems hardly reasonable to suppose that canals, 
which carry a portion of the nutritive fluids, should 
open externally.* 
2 Wagner, Zur vergleich. Physiol. d. Blutes. 
Hift. I. p. 19; aud Delle Chiaje, Descriz. I. p. 57. 
1 The form of the heart depends upon that of the 
posterior part of the body ; it is large in the gen- 
era with a short body, and elongated in those of a 
long body. According to Kélliker (Ann. of Nat. 
Hist. XVI. p. 414), Hectocotylus has also a 
heart communicating with arteries and veins, but 
he says nothing of its locality. 
2 See Owen, On the Nautilus, Pl. VI. fig. 1, or 
Isis. Taf. IV. or Ann. d. Sc. Nat. XXVIII. Pl. III. 
fig. 2; Brandt, loc. cit. Taf. XXXII. fig. 22; The 
Catal. of the Physiol. Ser. II. Pl. XXII. (Sepia) ; 
and Van Beneden, loc. cit. Pl. III. fig. 5 (Ar- 
gonauta). 
Often the two branchial arteries are widely di~ 
lated before entering the heart, and these dilata- 
tions may be regarded as auricles. 
3 See Cuvier, Mém. p. 22, Pl. IT. fig. 4 (Octo- 
pus); and Owen, Cyclop. I. p. 541, fig. 227 
(Onychoteuthis). 
4 For the distribution of the ophthalmic arteries. 
see Krohn, Noy. Act. Nat. Cur. XLX. pt. IL. p. 
47 
5 Delle Chiaje, loc. cit. Tav. LXXXVIII. XC. 
XCII. XCIV. (or 20, 28, 22, 24) has represented 
in detail the arterial system of Octopus vulgaris, 
Sepia officinalis, Loligo vulgaris and sagittata. 
*[§ 251, note 1.) For Milne Edwards’ beautiful figures see Régne anim. loc. cit. Pl. 1b, 1¢ 
(Octopus).— En. 
