REPTILIA. 



299 



. 2)8. 



Viscera of the Female Tortoise. (Emys Europceus.) The Lungs and Lymphatic Vessels have been removed, to 

 exhibit the Course of the principal Blood Vessels. 



A, arch of the right aorta ; B, arch of the left aorta ; c, the pancreas ; E, trachea ; E', E', right and left 

 bronchus ; F<, F', right and left subclavian arteries ; H, the clitoris, lodged in the cavity of the cloaca, 

 showing the deep urethral groove running along its dorsum ; i, i', lobes of the liver ; K, K', the stomach ; 

 L, common trunk formed by the union of the right and left aorta ; M", M', M', the right and left oviducts ; 

 N, the ovarium ; Q, termination of the urethral groove, at the extremity of the clitoris ; u, u, super- 

 numerary lateral bladders, opening by wide fissures into the cloaca on each side of the clitoris ; u', urinary 

 bladder ; x, the spleen ; d, vena-cava inferior, opening into the right auricle of the heart ; e f , g, h, i, 

 trunks of the jugular and subclavian veins. 



It is frequently connected with the com- 

 mencement of the intestinal canal. This is the 

 case in the Chelonian reptiles (Jig. 218. x.), 

 it is fixed to the duodenum, not far from the 

 pylorus, behind the opening of the ductus com- 

 inunis choledochus, and the head of the pan- 

 creas (c). In the Trionyx it, together with the 

 head of the pancreas, is inclosed between the 

 layers of the mesentery ; and in the Turtle is 

 contained in the first loop formed by the duo- 

 denum, close to the pylorus. In the Crocodile 

 of the Nile it is attached to the left side of 

 that portion of the intestine which imme- 

 diately succeeds the first loop ; whilst in the 

 Caiman it is placed between the layers of the 

 mesentery adhering to the second intestinal 



loop, close to the pancreas. In Lizards its 

 usual position is at the side of the stomach. 



The spleen in Ophidian reptiles belonging 

 to the genera Anguis and Cecilia, is situated 

 rather behind than in front of the pancreas, 

 close to the commencement of the intestine ; 

 but in all the true serpents it is situated in 

 front of the pancreas, to which it is closely 

 attached, or indeed sometimes imbedded in 

 its substance, receiving from it numerous 

 veins of large size, which sometimes appear 

 to form a sinus between the two organs, which 

 are moreover connected by fibrous bands, and 

 bound down by the same folds of peritoneum. 



The abdominal viscera of reptiles are re- 

 tained in situ by numerous mcsenteric folds, the 



