38 VERTEBRATA. REPTILIA. 



sets being placed in opposition to each other, so 

 that it is a real climbing foot : the tongue is long, 

 cylindrical, and capable of being protruded with great 

 swiftness at flies, which are taken by an adhesive 

 saliva at its extremity : the eyes are nearly covered 

 by the skin, and have the very singular property 

 of moving independently of each other. The lungs 

 are of enormous size, almost filling the abdomen, so 

 that when they are inflated, the animal is semi- 

 transparent, and hence it was supposed to feed on 

 air. The inflation of the lungs in different degrees, 

 is perhaps the cause of the changes of colour for 

 which this animal has been so celebrated. The skin 

 is yellow, and the blood of a lively violet blue. 

 The blood, then, projected from the heart to the 

 surface of the body in varying quantity and force, 

 according to the emotions of the animal, will cause 

 the surface to assume different shades of yellow, 

 green, blue, or grey ; which its other fluids may 

 also slightly influence. There are many species 

 common in the warm countries of the old continent, 

 and one, (C. Africanusj) even extends to southern 

 Europe. It is a harmless animal, and even useful, 

 as lessening the number of annoying insects. It is 

 extremely gentle in its manners. One may take it 

 in his hand, and put his finger into its mouth, with- 

 out any danger of being bitten.* It walks awk- 

 wardly in all situations, and therefore does not 

 pursue its insect prey, but, concealed beneath the 

 leaves, it waits for them to come within the reach of 



* Griffith. 



