33S :^IOLLUSCA. 



A fleshy funnel placed at the aperture of the sac, before the neck, affords an outlet 

 to the excretions. 



The Cephalopodes have two hrancliiao, one on each side of the sac, in the shape of a 

 compound fern-leaf. The great vena cava, ■^vlien between them, divides into two 

 branches, wliich terminate each in a fleshy ventricle, placed at the base of its respective 

 branchia, and propelling the blood into it. 



The two branchial veins tend to and terminate in a third ventricle, situated near the 

 bottom of the sac, whence the blood is carried to every part of the body by different 

 arteries. 



Respiration is effected by the water which enters into the sac, and is driven out 

 asain through the funnel. It ap]iears that the water even penetrates into tw"0 cavities 

 of the peritoneum, which the venie cavai cross in their course to the branchire ; and 

 that it has some influence on the venous blood, through the medium of a glandular 

 ajiparatus attached to these veins. 



The mouth opens amidst the bases of the feet. It has two powerful corneous jaws, 

 similar to the beak of a Parrot, and between the jaws is a tongue roughened with 

 horny ])rickles. The gullet swells out into a crop, and then passes into a gizzard as 

 fleshy as that of a bird, to which succeeds a third membranous and spiral stomach, 

 into wdiich the hver, which is very large, pours its bile through two conduits. The 

 intestine is simple and short. The rectum opcir* uito the funnel. 



These animals have a peculiar excretion of a deep black colour, which they use to 

 taint the water wlien concealment is necessary. It is secreted by a gland, and reserved 

 in a sac, difterently situated in difl'erent species. 



Their brain, inclosed in a cartilaginous cavity of the head, sends off from each side 

 a cord which swells, within each orljit, into a large ganglion, wdicnce are derived innu- 

 merable optic fllaments. The eye is formed of numerous membranes, and is covered 

 bv the skin, wdrich becomes transparent in )iassing over it, and sometimes forms folds 

 that supply the Avant of eyelids. The ear is merely a little cavity excavated on each 

 side near the brain, without semicircular canals or external passages, and in which 

 there is suspended a membranous sac, containing a little stone. 



The skin of these animals, particularly of the Octopus, changes colour, in patches 

 and in spots, wdth a rapidity greatly superior to that of the Chameleon.* 



The sexes are separate. I'he ovary of the female is at the bottom (if the sac. Two 

 oviducts caiTy the eggs from it, passing them through two large glands which envelope 

 them, during their passage, with a viscous fluid, and gather them together into a sort 

 of cluster. The testicle of the male, similar in iiosition to the ovary, gives oft" a vas 

 deferens that terminates in a fleshy penis sitvuited to the left of the anus. A vesicula 

 seminalis, and a prostate, also 0])en there. There is reason to believe that im]ireg- 

 nation is cH'ected bv a sprinkling of the seminal fluid o\'er the eggs, as illustrated 

 in the majoritv of Fishes, in the season of spawning, the vesicula contains a vast 

 numljer of little filiform bndies, A\hich, through a peculiar mechanism, writhe and 

 move about rapidly as soon as they fall into the water, and shed the fluid with \\hieh 

 they are Hlled. 



'I'nesc animais are voracious and savage ; and as they arc agile, and are furnished 



• Sec Carus. Nov .Id. A',;/, C,<r. xii. purl i. p. Ti^ft ; .iiid S.1n^i.,vaPllli, .I'm. rfci 5. i. A'.//, vol. xvl. y. 303. lALso ColiLslrc nm. in E.thihur^J, 

 Jiiurn. <:J N'tl. 'nid tJr<j^'ro[,!i . Scirtict-, vi,l. ii. p. ^lili.J 



