ABDOMINAL VISCERA. 



17 



1. The heart, enclosed in the pericardium, is situated in the 

 middle line in front, and in the natural condition of the parts 

 is covered by the pectoral girdle and the sternum. 



2. The liver, is a large reddish-brown bilobed organ, behind 

 and at the sides of the heart. 



3. The lungs are two thin-walled elastic sacs at the sides of the 

 heart : they lie dorsal to the liver, and are often hidden by it 



Note the bristles already passed into the lungs through the glottis. 



4. The corpora adiposa, or fat bodies, are two bright yellow 

 tufts of flattened processes attached to the dorsal wall of the 

 body cavity ; they vary much in size, and usually come to the 

 surface just behind the liver. 



5 The small intestine is a light coloured convoluted tube; 

 in the middle line behind is the much wider large intestine. 



6. The Madder is a thin-walled bilobed sac at the posterior 

 end of the body cavity. 



Fig. 2. A diagrammatic transverse section across the posterior part of 

 the body of a female frog. 



a, urostyle : h, muscles of body wall : d, large intestine : d.a, dorsal 

 aorta : i, ilium : I, lymph space between the skin and the muscular body 

 wall : 11, spinal nerves : o, kidney : ov, oviduct : p, peritoneum : s, skin : 

 t, fold of skin at groin : u, ureter : v, posterior vena cava. 



7. lyi the female frog note, in addition to the above jmrts, 

 a. The ovaries : two large bodies of irregular shape, each 

 consisting of a mass of spherical black and white 

 eggs, like small shot. 

 C 



