THE LIZARD. 



107 



are convex, while at the 

 forepart they are con- 

 cave. Each of the four 

 limbs is terminated by 

 five digits. 



The organs of sense 

 are much like those of 

 the bird. The tongue 

 is forked. The eyes are 

 furnished with a nicta- 

 ting membrane or third 

 eyelid. The ears have 

 no pavilion and no ex- 

 ternal meatus, so that 

 the tympanum is on a 

 level with the skin. 



The olfactory lobes 

 are placed in front of 

 the cerebral hemi- 

 spheres, and these lat- 

 ter are separated from 

 the cerebellum by the 

 optic thalami. In brief, 

 those parts of the brain 

 that in mammals and 

 birds are massed to- 

 gether are in the lizard 

 spread out and grouped 

 in linear series, the ones 

 behind the others. 



Like all other animals 

 of the class of reptiles, 

 and like birds, the lizard 



