290 $ 258. 
THE CEPHALOPODA. 
CHAPTER VIII. 
RESPIRATORY ORGANS. 
§ 253. 
All the Cephalopoda respire by means of Branchiae. These are situ- 
ated in the cavity of the mantle, separated from the other viscera, and out- 
side of the peritoneum. Hectocotylus forms the only exception in this 
respect, — its branchiae being free, and placed along the sides of the ante- 
rior half of the body under the form of numerous oblong, thin, thickly- 
set lamellae.” Nawtzlus has, on each side, two branchiae, while the other 
Cephalopoda have only one. 
These organs have a more or less oblong, pyramidal form, and are 
attached, at one of their borders, to the external surface of the mantle by 
a thin cutaneous fold, — leaving their extremity to extend freely in front. 
The adherent edge is bordered by the trunk of the branchial artery, and by 
a large glandular band,® while the free border is occupied, from its base 
to the top, by the principal branchial vein. With Nautzlus, and the Loli- 
gina, there are, between these vessels, numerous, triangular, branchial lam- 
ellae lying upon each other, and plicated upon both surfaces. But with 
the Octopoda, these lamellae are replaced by arches, which, on each side, 
pass from one vascular trunk to another, and have, upon their convex edge, 
a multi-plicated membranous band.® The branchial vessels extend from 
the branchial artery to the branchial vein through the lamellae and the 
branchial arches; and in this passage, the venous is changed to arterial 
blood. As there is no ciliated epithelium on the surface of the branch- 
jae, the water is renewed exclusively by the rhythmical respiratory move- 
ments.© It enters, from both sides of the funnel, into the interior of the 
mantle when its borders are open, and is ejected through the funnel by the 
contractions of the mantle when its borders are closed.” 
1 I have found such with Hectocotylus tremoc- 
topodis ; according to Mélliker (loc. cit.) that of 
Argonauta has also branchiae. 
2 This glandular body has been regarded by 
Cuvier (Mém. p. 20, Pl. I. fig. 3, Pl. ILI. fig. 1, 
A.) and other zootomists as a muscular stripe; 
while Mayer (Analekten, &c., p. 56, Taf. V. fig. 
1, No. 14), from its cellulo-vascular texture, has 
taken it fur aspleen. I have been unable to find in 
‘itany muscular fibres, but o1.ly numerous cells, and 
I am of the opinion that this enigmatical organ 
holds some special relations with the venous system. 
3 See Owen, On the Nautilus, p. 30, Pl. VI. fig. 
1, 4, or Isis, p. 26, Taf. IV., or Ann. d. Sc. Nat. p. 
124, Pl. ILL. fig. 2, 3, and Valenczennes, loc. cit. 
p. 281, Pl. IX. X.; The Catalog. of the Physiol. 
Ser. IL. Pl. XXI. XXII. (Sepia); Treviranus, 
Beobacht. ans. d. Zoot. u. Physiol. p. 37, Taf. VIII. 
fig. 52-54; Grant, Transact. of the Zool. Soc. I. Pl. 
IL. XI. (Loligopsis and Sepiola) ; Cuvier, Mém. 
. 20, Pl. IL. WIL.; Delle Chiaje, Descriz. Tay. 
Kix’ fig. 1-5 (Octopus); and Férussac, loc. cit. 
4 The number of the branchial lamellae and 
arches varies very much. With Nautilus, each 
branchia is composed of a double row of forty-eight 
lamellae ; the long-bodied Loligina have a double 
row also, composed of sixty to ninety lamellae. 
With Sepia, there are thirty pairs ; and with the 
Octopoda, the number of branchial arches is still 
less ; there are only fifteen pairs with Argonauta, 
and twelve alone with Octopus, and Eledone. 
5 For the distribution of the blood-vessels in the 
branchiae of Sepia, see Tilesius, De Respirat. Se- 
piae officinalis, Tab. I. II. 
6 That, with the Cephalopoda, which are in gen- 
eral so poor in cilia, there should be no ciliated 
epithelium on the branchiae, is so remarkable a 
fact, that I have had it confirmed from fresh speci- 
mens by my friend H. Koch at Trieste, although 
Sharpey (Cyclop. I. p. 619) had already spoken of 
it. ea 
7 For these respiratory movements, see Grav- 
enhorst, Tergestina, p. 1, and Wagner, in tho 
Isis, 1833, p. 159. 
