588 



Marvels of the Universe 



'fe^-'^^fe- 





Head of female of Johnston's Chame- 

 leon. Note that the female has no traces 

 of the three horns so pronninent in the 

 male. 



fop of ihe head of the Long-nosed 



Ch 



ameleon 



nale specimen. 



Africa, possiblj' from some 



group related to the Agama 



lizards of the Old ^^■orld. 



They develop about twenty- 

 five different species in 



Madagascar, where they are 



represented by two genera, 



one of which contains the 



smallest known Chameleons. 



One of these species is less 



than three inches in length. 



On the other hand, in 



Madagascar is also found the 



Giant Chameleon, which is 



two feet long. Only one 



species is found in Southern 



India and Ceylon, but it 



is sometimes stated that 



there is a sec(jnd tj'pe of 

 Chameleon in the last-named island. This is a very excusable mistake, aiising from one of the 

 most remarkable cases of mimicry known in nature. A gexus of Agama lizards has acquired the 

 most extraordinary external resemblance to Chameleons, having just the same shaped head, with 

 excrescences like horns, the same serrated back and hunched-up body, but can, however, be 

 distinguished from the real Chameleons by the fact that its tail is not really prehensile, and, still 

 more, by the arrangement of the fingers and toes. In this imitative Agama lizard the thumb and 

 the fifth toe are opposed to the other digits ; but in the true Chameleons, not only is the tail very 

 prehensile, but the fingers and toes are arranged in groups of three and two for the purposes of 

 grasping, instead of four and one. 



Another remarkable feature in the structure of Chameleons is the large revolving eyeballs, 



which can be turned inde- 

 pendently one of the other, 

 ^ so that they can direct the 



sight of either eye simul- 

 taneously in all directions. 



The actual eye opening is 



small. Another strange de- 

 velopment is in the immense 



club-shaped tongue, which 



has a long, narrow root of 



elastic fibres. The tongue 



is retracted in a telescope 



fashion into the capacious 



throat, but it can be most 



rapidly ejected to a length 



nearly equalling that of 



the animal's bod}'. The 



Top of the heacf of the male John- 

 ston's Chameleon. shelving the three 

 horns. 



club-shaped end of the 

 tongue really consists of two 

 flaps, which can open and 



Head of the female Long-nosed Chame- 

 leon, in which the strange projections or 

 the nasal bcnes and forehead are only 

 just indicated. 



