18 GENERAL ANATOMY OF THE FROG. 
a, urostyle: b, muscles of body wall: d, large intestine: d.a, dorsal ares = 
2, ilium: l, lymph space between the skin and the muscular body wall : 
spinal nerves: 0, kidney; 0.v, oviduct: p, peritoneum: s, skin: f, fold of 
skin at groin: u, ureter: v, vena cava inferior. 
Notice the thin pigmented membrane—the peritoneum— 
which lines the body cavity. Trace this to the mid-dorsal line 
where it is reflected downwards as a double layer—the mesen- 
tery—which embraces at its edge the alimentary canal. 
_ 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, 
wis Wig 
Fig. 8. General view of thie) viscera wet the an frog, from the right side. 
a, stomach: 6, bladder: c, small intestine: cl, cloacal aperture: d, large 
intestine: e, liver: f. bile duct: g, gall bladder : h, spleen: 7, lung: k, 
larynx: 1, fat body: m, testis: n, ureter: 0, kidney: , pancreas: 7, pelvic 
symphysis : s, cerebral hemisphere: sp, spinal cord: ¢, tongue: 4, auricle : 
ur, urostyle: v, ventricle: v.s, vesicula seminalis: Os optic lobe: #, cere- 
bellum: y, Eustachian recess: 2, nasal sac. 
Turn the liver forwards, and note the stomach lying beneath its 
left lobe. Pass the handle of the seeker through the mouth and 
down the esophagus into the stomach. 
