182 



REPTILES AND FISH 



The period required for development is stated to be 

 twelve weeks. ^ 



Note. — Only in the first case was every egg examined, and the number 

 that had failed to develop is surprising. In view of this fact it is to be 

 regretted that subsequently only a few from each nest were broken open. 



The Monitor Lizard. 



By far the most notable reptile on the islands is the 

 enormous Monitor Lizard {Varanus niloticus), called by 

 the natives " Enswa-swa." It is of a dull grey colour 

 speckled with yellow, and its long tail is flattened from 

 side to side for swimming. This fine creature may 

 measure almost six feet from nose to tail tip. It 

 is never found far from the water, into which it rushes 

 headlong when disturbed, so that its panic-stricken flight 

 is very often heard as one pushes through the dense 

 vegetation bordering the shore. In the water the Enswa- 

 swa swims with vigorous strokes of the flattened tail, 

 and may often be seen lazily sculling itself along with the 

 top of the head just above the surface. When alarmed 

 it hastily dives, and can remain under water for a 

 ^ Gadow, Cambridge Natural History, vol. Reptiles, p. 465. 



