DESCRIPTION OF PLATES. 317 



PLATE VII, 



Exhibits a reduced view of a part of the Mesentery of a Turtle 

 injected. The Arteries were filled with red Wax, the 

 Veins with black, and the Lacteals with Mercury. 



The mesenteric artery and vein, as they pass on to the gut 

 between two folds of the peritoneum, divide into branches that 

 make frequent anastomoses. These larger vessels leave spaces 

 that resemble a network, and form meshes of different sizes. 

 These in the unprepared state are transparent ; but when the 

 blood-vessels are minutely injected, we observe several small 

 arteries and veins ramifying to the utmost minuteness. And 

 from the transparency of the peritoneum, we can here distinctly 

 trace the artery terminating in the vein by continuity of canal. 

 It is on these meshes that the lacteals, as they come from the 

 gut upon the mesentery, divide into innumerable branches, that 

 communicate frequently with each other, and form a beautiful 

 plexus of lacteal vessels. That in its office, we consider 

 analogous to the lymphatic glands, seen in the mesentery of 

 other animals. 



0, a, a, a, a, The outline of the mesentery. 



by b, by The intestine. 



c, The artery. 



d, The vein. 



e, The lacteals surrounding the artery and vein. 



A, A mesh of the mesentery on which a plexus of lacteal 

 vessels is delineated. 



