REPTILIA. 563 



In theCHELONiAN,the SAURIAN, and tlieBATiiACHiAN orders, tlie 

 substance of the tongue seems to be principally made up of a thick 

 glandular mass, formed by a multitude of little tubes united at 

 their bases, but, becoming separate towards the surface of the 

 tongue, they give the whole organ a papillose or velvety appear- 

 ance. This glandular apparatus rests immediately on the muscles 

 of the tongue, and upon its sides a multitude of pores are visible 

 through which the salivary secretion exudes. 



(621.) In the OPHIDIAN REPTILES, from the manner in which 

 they swallow their prey, the bulk of the tongue is necessarily re- 

 duced to the utmost extent ; the whole organ seems converted into 

 a slender bifid instrument of touch, and is covered with a delicate 

 membrane. Instead of the salivary apparatus described in the last 

 paragragh, two glandular organs (Jig. 251, s, ), placed immediately 

 beneath the skin of the gums, surround the margins both of the 

 upper and lower jaws ; and from these an abundant salivary secre- 

 tion is poured into the mouth, through orifices situated externally 

 to the bases of the teeth. 



(622.) The Liver of Reptiles (Jig. 254, h) requires no parti- 

 cular description : its secretion, as well as that of the pancreas 

 (Jig. 254, o), is poured into the intestine in the usual manner at a 

 little distance from the pylorus. 



(623.) The Spleen, and system of the Vena Porta^ are dis- 

 posed in the same manner as in other Vertebrata. The spleen 

 (Jig- 254, /) is generally more or less closely connected with the 

 stomach ; and the large vein derived from it, being joined by those 

 proceeding from the other viscera of the abdomen, forms the trunk 

 of the portal vein (wi), which soon divides again into numerous 

 branches that ramify in the substance of the liver. 



(624.) The Lymphatic and Lacteal systems are very im- 

 portant parts of the economy of these creatures ; and, from the 

 large size of the absorbent vessels, their disposition is more easily 

 traced in the class before us than in any other. The principal 

 trunks surround the aorta and other large blood-vessels, and com- 

 municate very extensively with the veins in different parts of the 

 body. From the imperfect condition of the valves in their inte- 

 rior, the lacteals of many tribes may be readily injected from 

 trunk to branch ; and, when thus filled with mercury, they are 

 found to spread out between the coats of the intestines like a 

 dense network of silver. 



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