CHAMELEONS. 139 



even black, either in portions, or all over their bodies. These 

 changes of colour were for a long time attributed to the greater 

 or less distention of the vast lungs they possess, and to the 

 corresponding modifications in the quantity of blood sent to the 

 skin ; but this explanation is now abandoned. According to 

 Mr. Milne Edwards, the cause of these variations of colour lie 

 in the peculiar structure of their skin, in which there exists two 

 layers of membranous pigment, placed the one above the other, 

 but disposed in such a manner as to appear simultaneously under 

 the cuticle, and at other times so that the one hides the other. 

 Again, occasionally the cuticle is hidden under the superficial 

 pigment. 



[Sixteen or seventeen species of Chameleon are described in the 

 British Museum Catalogue. 



I. Having an erect fin on the back, the belly crested ; which 

 includes the Fringed Chameleon, C. cristatus, a native of Fer- 

 nando Po. 



II. Having the back high, and compressed belly and sides, 

 with a toothed crest ; including the Side-crested Chameleon, 

 C. laterales, a native of Madagascar. 



III. The back and belly having a toothed crest, the sides 

 simple, the scales small and equal, muzzle simple; including 

 the Common Chameleon, C. vulgaris, with many synonyms. It 

 is a native of the East Indies, is the recognised type of the family 

 (Fig. 32), and the one most commonly brought to England. 

 There are probably two varieties, one from North Africa, which 

 is also found in Sicily and the South of Spain ; the other, the 

 East Indian variety C. Senegalensis, the Senegal Chameleon, 

 a native of West Africa ; C. arpelis, from Ashantee and Ga- 

 boon ; C. verrucosus, a native of Bourbon and Madagascar ; 

 the Rhinoceros Chameleon, C. rhinoceroceratus, also from Mada- 

 gascar. 



IV. Having a toothed crest on the back, with the belly and 

 sides simple, the chin and muzzle simple ; including C. tuber- 

 culiferus, a native of South Africa ; C. cucullatus, the Hooded 

 Chameleon, a native of Madagascar ; C. nasutus, having the chin 

 simple, and the muzzle compressed, and C. bifurcus, having the 

 muzzle in the male forked both natives of Madagascar ; C. 



