18 BRITISH LIZARDS 



aperture just behind the posterior angle of the mouth 

 (with the delicate tympanic membrane covering) ; and, 

 lastly, the anal or cloacal opening at the root of the 

 tail — a transverse slit. 



Coming now to the internal structure of the lizard, 

 we note first the alimentary tract. On the floor of 

 the mouth is the long narrow tongue, bifid in front, 

 but not so deeply divided as in a snake. The teeth 

 are small and conical, and there are, of course, no 

 fangs. The gullet or oesophagus leads to the stomach, 

 which lies under the liver. The stomach is a strong 

 muscular tube which is continued as the small in- 

 testine, this in its turn ending in the large intestine 

 and rectum. The rectum is of greater dimensions 

 transversely, and gives off a small pouch, the 

 caecum. 



The liver is a large brown organ in the middle 

 of the body with a duct to the gall-bladder, the latter 

 being usually recognisable by its green colour from the 

 bile within it. The pancreas is a narrow whitish 

 structure between the stomach and intestine, and the 

 small reddish spleen is near the posterior end of the 

 stomach. In the male, the two oval white testes will 

 be seen, the right one being placed farther forwards 

 than the left. In the female, the two ovaries are 

 situated rather more posteriorly than the testes in 

 the male, and show rounded elevations, due to the 

 eggs within. The urinary bladder is a thin sac. 

 There are two kidneys, dark brown in colour, each 



