112 



OBSERYATIONS UPON THE LIVER. 



The general shape of the liver and viscera corresponds with 

 that of the abdominal cavity and the fish. 



In the Garfish, a long round fish having a correspondingly 

 long and round abdominal cavity, the liver is elongated and 

 resembles in appearance that of the doubtful reptiles and Ophi- 

 dians. See Figure 11, representing the liver and viscera of 

 the salt-water Garfish [Lepisosteus osseus). 



In the Congo Snake (Amphiuma means) (Fig. 20), a long, 

 slender, doubtful reptile, with an elongated narrow abdominal 

 cavity, the general form of the liver is that of a long irregularly- 

 shaped prism. 



In the shorter and stouter Hellbender {Meviopoma Alleganen- 

 sis) and Menobranchus maculatus, this organ is correspondingly 

 broad and short. 



The liver of Batrachians generally consists of three lobes, and 

 occupies the superior middle portion of the abdominal cavity. 



This organ in serpents is narrow and much elongated, cor- 

 responding to the shape of the abdominal cavity, whilst in the 

 round, thick-set Chelonians, it consists of two principal lobes 

 extending across the abdominal cavity. These lobes in the 

 Chelonia are united by a small isthmus, and resemble a pair 

 of saddlebags. 



Fig. 21 represents the viscera of a Corn-Snake [Coluber gut- 

 iatus) This may be compared with Figs. 8, 9, 11, 19, and 20. 



These differences corresponding to the general form of the 

 animals, will be readily comprehended by comparing together 

 the following figures : — 



Fig. 19. Viscera of Stingray {Trygon sabina). 



" 11. " Garfish (Lepisosteus osseus). 



" 20. " Congo Snake {Amphiuma means). 



" 21. " Corn Snake (Coluber constrictor). 



" 8. " Snapping Turtle (Chelonura serpentina). 



" 9. " Gopher (Testudo polyphemus). 



The size of the liver also varies much, and, as far as my 

 observations have extended, the difference can be accounted 

 for neither by the habits, nor by the vital, chemical, or physi- 

 cal constitution of animals. The truth of this assertion will 

 be readily verified by a reference to the following table of the 

 relative weights of the livers of different animals, which were 

 carefully ascertained upon delicate balances. 



Viscera of Corn Snake (Coluber constrictor), reduced one-half diameter. C. Trachea or -windpipe. A. Auricles of 

 heart. B. Ventricle of heart. F. Superior vascular portion of the lung. D. ffisophagus. G, G. Liver. S. Sto- 

 mach. M. Gall-bladder. N. Spleen. The hepatic duct is seen passing over the spleen and perforating the pan- 

 creas. P. Pancreas, compact ovoid gland attached to the small intestine. R. Divided end of small intestine. 



