20 GENERAL ANATOMY OF THE FROO 



b. The oviducts : two long, very much convoluted tubes with 

 thick white walls, lying at the sides of the body cavity. 

 7. In the male frog note, 



a. The testes : a pair of ovoid bodies of a pale yellow 

 colour, attached to the dorsal wall of the body cavity. 



Notice the thin pigmented membrane the peritoneum 

 which lines the body cavity or coelom, covered by coelomic epi- 

 thelium. Trace this to the mid-dorsal line, where it is reflected 

 downwards as a double layer the mesentery which embraces 

 at its edge the alimentary canal, and binds its several coils 

 together. (See Fig. 2.) 



Notice also that all the abdominal viscera are really outside 

 the peritoneum, which forms a closed sac into which the viscera 

 are as it were pushed from without. 



E. The Digestive Organs. 



FIG. 3. General view of the viscera of the male frog, from the 

 right side. 



a, stomach ; b, bladder ; c, small intestine ; cl, cloacal aperture ; 

 d, large intestine ; e, liver ; /, bile duct ; g, gall bladder; h, spleen ; 

 ', lung; k, larynx; /, fat body; m, testis ; n, ureter; o, kidney; 

 p, pancreas; r, pelvic symphysis ; s. ceiebral hemisphere; s/>, spinal 

 cotd ; /, tongue; u, auricle; ur, urostvle ; v, ventricle; v.s, vsicula 

 seminalis ; w, optic lobe; *, cerebellum; y, Eustachian recess; 

 s, nasal sac. 



