FISHES. 361 



very often form dense meshes, and in several, layers. By means of 

 injections we can follow them upon the borders of the valvula? eonni- 

 ventes, and other internal folds of the velvetty surface. They termi- 

 nate by various trunks in the great venous sinus or in any of the prin- 

 cipal veins which approach it. 



There is no difficulty whatever in obtaining a sight of these of the 

 other parts, and M. Fohmann has injected those of the branchiae 

 amongst others with success; we should, therefore, conclude that 

 nature adopts in this class the same contrivances for absorption, as in 

 the other oviparous vertebrated animals*. 



Circulation^. 



Fishes have, as well as warm-blooded animals, a complete circula- 

 tion for their body, another equally complete for the respiratory 

 organs, and a peculiar abdominal circulation terminating in the 

 liver by the vena porta? ; but their appropriate character consists in 

 this, that their branchial circulation has alone at its base a mus- 

 cular apparatus, or a heart corresponding with the auricle and the 

 right ventricle of the animals just mentioned, and that there is nothing 

 at all like it at the base of the circulatory system of the body, that is 

 to say, that the analogues of the auricle and right ventricle are 

 entirely wanted, and that the branchial veins are converted into 

 arteries without being enveloped with muscles. 



* See the fine work which M. Fohmann has just published on the lymphatics of 

 fishes, forming' a first part of a general history of these vessels in the vertebrated 

 animals; Heidelberg and Leipsic, 1827, in folio. He represents them in the torpedo, 

 in the eel, pike, and some portions of silurus and anarrhicus, and of the cod and 

 salmon. Munro gave a representation of those of the ray in his Anatomy and 

 Physiology of Fishes, pi. 18, 19. 



f Duverney, in his Memoirs of the Academy for 1791, and in his Works, vol. ii. 

 p. 496, and pi. 9, has described the whole of the apparatus of the circulation and 

 respiration of fishes, and makes a calculation of the frightful number of perceptible 

 parts of which he composes it ; in those of 1699, he has given a very particular de- 

 scription of that of the carp, which is also to be found in his Works, loc. cit. p. 470. 

 Munro, in his Anat. and Physiol, of Fishes, has represented the principal trunks 

 of the vascular system in the ray ; the branchial veins and arteries of the body 

 which spring from them, pi. 1 ; the great venous sinus and branchial arteries, 

 pi. 2 ; the abdominal arteries and the vena portae, pi. 3. Koelreuter has given the 

 figure of the heart of a sterlet. (Nov. comm. petrop. vol. xvi. p. 14). Vicq d'Azyr 

 in the Mem. des Sav. Etr. vol. vii. pi. 7, gives very badly the barbel and plaice. 

 There is a treatise, ex professo, on the heart of fishes by M. Tiedemann (in German, 

 Landshut, 1809), with figures of the hearts of the ringed ray, of the bukeled ray, of 

 the white ray, of the shark (sq\ialus), the emissole (mustellus), the sturgeon, 

 conger, murena, otter-pike, lote, sole, barbel, scorpcena, the arcuated cha:todon, of 

 one of the barbel, scisena, of the saurel, orphi, of the fistularia, of the lauricaria, of the 

 grayling, of the trout, sea-trout, huch, mullet, pike, carp, and another barbel. See 

 also on the heart of fishes, Peyer, Miscell. ac. cur., dec. 11. ami. 1. p. 201, taken 

 from the salmon. Muralt, ib., p. 124, of the lote; Collins, pi. 15, fig. V, of a 

 salmon. Al. Munro Anat. and Phys. of Fishes, pi. 18. fig. I and II of salmon ; 

 pi. 22, fig. I, of the cod. Koelpin, mem. de l'acad. de Stockholm, in 1769, of 

 the sword-fish. G. Needham, De Biolychnio, and Valentin, Amph. Zoot. vol. 

 2, p. 122, of the pike. J. Plancus, Comm. bonon. vol. 2, pi. 11, p. 297, of 

 tetrodon mola. Doellingcr, Memoires de la Societe de Vetteravie, vol. 2, second 

 part, pi. 13, fig. I, of the carp. 



