214 



THE FROG— THE PLATANA 



2. Remove the whole of the alimentary canal, with the liver, pancreas, and 

 spleen, by cutting through the oesophagus and the large intestine (where it joins 

 the cloaca), and detaching it from the roof of the body-cavity without injuring 

 the kidneys and the reproductive organs. 



Draw the complete alimentary canal. 



Urino-genital System. 



Note the kidneys, two elongated flattened dark-red organs Ipng one on 

 each side of the vertebral column towards the posterior end of the abdominal 

 cavity. From the outer edge of each kidney a duct, the ureter, passes back- 

 wards, and opens into the cloaca on the dorsal side, opposite the opening of 

 the bladder. On the ventral sides of the kidneys the adrenal bodies appear 

 as small yellow patches. [In the Platana these adrenal glands are apparently 

 absent.] 



In the male Frog note : 



(a) The testes, a pair of ovoid pale yellow bodies attached to the dorsal wall 

 of the body-cavity by a fold of peritoneum. They lie on the ventral 

 sides of the kidneys and are connected to them by short efferent ducts 

 (vasa efferentia) which pass into the kidneys. 



Testis 



Kidney 



Corpora- 

 **- adiposa 



Kidney 



Ureter 



Vesicula seminalis 



Bladder 



A B 



Fic. 74. — A. The Urino-genital System (male) of Rana; and B. of Xenopus. 



