ABDOMINAL VISCERA 



19 



Inflate the lungs with a blow-pipe through the glottis, and inflate 

 the bladder through the cloacal aperture. 



Note and draw the general arrangement of the viscera, showing 

 the following structures: 



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

 middle ventral line, 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 small intestine is a light-coloured convoluted tube ; 

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



5. The bladder 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; i>, muscles of body wall ; d, large intestine ; d.a, dorsal 

 aorta ; i, ilium ; /, lymph space between the skin and the muscular 

 body-wall (cisterna lymphatica magna) ; , spinal nerves ; o, kidney ; 

 ov, oviduct ; p, peritoneum ; s, skin ; /, fold of skin at groin ; u, ureter ; 

 v, posterior vena cava. 



6. In the female frog note, in addition to the above parts, 

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

 consisting of a mass of spherical black and white 

 eggs, like small shot. 



