REPTILES. 285 



gature, and thus, by retarding the circulation, give time 

 tor the poison to become diluted and neutralised by the lo- 

 cal fluids. These remedies are obviously such, as, in ordi- 

 nary cases, should be resorted to. On the other hand, 

 some recommend the internal and external use of ammonia, 

 the external application of caustic potash, or of heated tur- 

 pentine. Many vegetables have likewise been employed as 

 antidotes. The subject, however, though one of great inte- 

 rest, is in some measure unexplored, and can only receive 

 useful illustration from the researches of those who reside 

 in the districts where the larger and more venomous spe- 

 cies so frequently prove destructive to human life. 



The tongue is usually slender, divided at the extremity, 

 and sheathed at the base. The alimentary canal is short 

 in proportion to the size of the body. The gullet and sto- 

 mach are capable of great dilatation, to receive the large ani- 

 mals which are swallowed. Digestion takes place slowly. 

 The liver is, in general, uniform in its appearance, and near- 

 ly entire. There is a gall-bladder. The spleen is of a 

 lengthened form, and placed at the commencement of the 

 intestines. 



The heart possesses two auricles and one ventricle. The 

 portion of blood transmitted for aeration, is returned by 

 a systemic vein, to the systemic auricle, from this it 

 passes into the common ventricle, which receives, through 

 the other auricle, the blood returned from the body. 



All serpents breathe air. Though many species can dive, 

 they are compelled to return, at intervals, to the surface of the 

 water, in order to respire. The larynx is too simple and 

 membranaceous to admit of the existence of voice. A hissing 

 sound, however, can be produced. The trachea is a mem- 

 branaceous tube, terminating directly in the lungs, without 

 the usual bronchial divisions. The lungs are single, in the 



