^ 223. THE CEPHALOPnORA. 253 



pal pulmonary vein. Its excretory duct accompanies the rectum and 

 often opens near the anus/'^ 



The kidney is nearly always of a dirty yellow, or reddish color, of a 

 lamellatcd structure, and its surface is wholly without vibratile organs. It 

 is surrounded by a sac-like envelope which is continuous with the inter- 

 nally ciliated, excretory duct. Each renal lamella is composed of thickly-, 

 set, delicate cells loosely bound together. In their transparent liquid floats 

 an obscure nucleus which, by direct light, appears brown or violet. 



These nuclei, which are round and embossed, have a very dense crystalline 

 structure, and are undoubtedly a product of the renal secretion.'-^ Cer- 

 tainly they contain the uric acid which is found when the whole gland is 

 chemically analyzed.*'^* The ramified canals upon the membranous en- 

 velope of the kidneys, return, probably, the blood into the respiratory 

 organs. But in the gland itself no blood-vessel has been observed.^*' 



With Sagitta, and the other Pteropoda, nothing like a renal organ has 

 yet been found. With the Heteropoda, and Apneusta, on the contrary, 

 there are vestiges of certain organs which further researches may show to 

 be of a urinary nature.*^' 



With the Pectinibranchia, the kidney is replaced by a gland which 

 is situated behind the branchia, between the heart and liver, and which, in 

 some marine species, secretes the purple liquid. 



It is composed of several ramified lamellae, and opens by a large orifice, 

 or by a duct of variable length which accompanies the rectum, at the base 

 of the branchial cavity.*'" With the other branchia ted Gasteropoda, the 

 existence of this gland is yet doubtful, although with most of them, and 



1 This is the gland which, with the Gasteropoda, a urinary gland. The long, yellow ciliated body, 

 has been considered by the older anatomists such but without excretory organs, which Nordmann 

 as Swammerdamm, Poli, and Blumenbach, asan (loc. cit. p. 24, Taf. II. Q.) observed with Ter^ipes, 

 organ secreting the calcareous salts, and by Cuvier between the stomach, Uver, heart and rectum, is 

 as a muciparous gland. also, perhaps, a kidney ; at all events, as such 



2 This gland corresponds, consequently, as to its cannot be regarded another and neighboring body, 

 position and intimate structure, to the bodies of larger, lobulated and of a yellowish color, having 

 Bojanus, which, with the Lamellibranchia, have apparently an excretory canal opening externally, 

 been considered as kidneys ; excepting that they and which ah-eady has been mentioned as being an 

 have no ciliated organs. For the intimate struc- hepatic gland. Perhaps a like interpretation 

 ture of the kidneys of Gasteropoda, see H. Meckel, should also be put upon the yellow bodies observed 

 in Muller's Arch. 1846, p. 13, Taf. I. by (^ualTefagen in the posterior part of the body 



3 Jacobson (Jour, de Physique, XCI. p. 318, or of Zephyrina, Actaeon, and Amphorina (Ann. d. 

 MeckePx Arch. VI. 1820, p. 370) was the lirst who Sc. Nat. I. p. 136, PI. IV. lig. 1-3). 



showed the presence of uric acid in this gland, with 6 With Tritonium, und Murex, this gland 



Helix pomatia, and nemorali.i, Limax niger, opens by a large orifice into the cavity of the man- 



Lymnaeus stagnalis, and Planorbis cornea, tie ; see Eysenhardt (Meckel's Deutsch. Arch. 



But, iome time previous, Dolling-er -And fVohiilic/i VIII. p. 216, Taf. III. fig. 4, r.), and Leiblein 



(Diss, de Helice pomatia, Wirceb. 1813, p. 23) had (ffeMSrn^er's Zeitsch. fiird. Organ. Phys. I. p. 4, 



regarded this organ as a kidney. The presence of Taf. I. h. i., or Ann. d. Sc. Nat. XIV. 1828, p. 179, 



uric acid can be easily shown in the dried kidneys PI. X. h. i.). A similar urinary gland has been 



of Helix pomatia and Paliidina vivipara, for described with Janthina, hy Delle Chiaje (De- 



when treated with nitric acid and ammonia, a con- scriz. II. p. 108, Tav. LXVII. fig. 3, e., L.'CVIII. 



siderable quantity of murexid is disengaged. fig. 14, i. 1.), as an accessory respiratory cavity. 



4 According to Treviranus (Beobacht. aus. d. With Paludina, this gland has a quite long ex- 

 Anat. u. Physiol, p. 39), with Helix and Avion, a cretory duct ; see Cuvier, Mem. loc. cit. fig. 3, 1. 7, 

 portion of the blood of the lungs, instead of going p. q. The kidney has, moreover, been described 

 to the lieart, passes into the kidneys, and thence by Cuvier (loc. cit.), and (^uoy and Gaimard 

 enters the great pulmonary vein. IJut it must be (Voy. de I'Astrolabe Zool. II. or, Isis, 1834, p. 285, 

 very difficult to show the course of this liquid in 1836, p. 31) under the names of Muciparous 

 the interior of the kidneys. gland. Organ of the purple, and Depurating or- 



5 The spongy substance mentioned by Delle gan, with Ptiasianella, Turbo, Buccinuvi, Mi- 

 Chiaje ^Descriz. II. p. 96, Tav. LXIII. fig. 3, tra, Oliva, Capraea, Harpa, Dolium, Cassis, 

 8.) as existing near the heart and at the base of Purpura, Fusus, Auricula, kc* 



the branchiae, with Carinaria, is undoubtedly 



* [ § 223, note 6.] For the renal organs with Paludina, see Leydig, Ueber Paludina vivipara, &c., 

 loc. cit. p. ISO, Taf. XUI. fig. 49, 0. — Ed. 



22 



