39() LIZARDS. 



motionless, stationed upon a branch, uatil the unconscious prey comes 

 within reach, when in a moment the tongue is darted forth, and 

 the insect is caught and swallowed. Then- power of changing 

 colour is wonderful, accurately imitating the tints of the leaves and 

 branches around tliem; so that their presence is not discoverable 

 except upon close inspection. 



The Crocodiles (CrocodUus), sometimes classed as 

 a distinct order, under the name of Loricata, are the 

 giants of the Eeptile race, some of them attaining 

 the length of twenty-five feet ; and as they are 

 strong, ferocious, and cunning, they may rank 

 among the most formidable animals. In their 

 general form they agree with the Lizards, but they 

 are distinguished by several imj^ortant characters. 



Of these, the most tangible and ob^dous is that 

 the whole back part of the neck, body, and tail is 

 clad with distinct series of bony plates embedded, 

 as it were, in the substance of the skin, and covered 

 externally with a thick cuticle. These dermal bones 

 are exceedingly strong, and they altogether form a 

 panoply of defence, capable of resisting the attacks of 

 the most powerful enemies. The bones of the head 

 in the Crocodile are more consolidated than those of 

 most reptiles ; the lower jaw is prolonged behind 

 the base of the skull, and this structure causes •the 

 upper jaw to seem moveable. There is in each jaw 

 a single row of teeth, which are conical in 

 form. A cavity at the root of each tooth 

 serves as a case or slieath for the germ of 

 the tooth destined to replace it ; and each 

 being thus gradually pushed out by a 

 successor ready to supply its place, the 

 mouth of the Crocodiles presents at all ages 

 its formidable array of pointed teeth in 

 undiminished number. The tongue is flat, 

 and free only at the very edge, so that 

 these unwieldy animals have often been 

 "^^ described as destitute of a tono-ue. The 

 Fig. 329.-TOOTH fr^ce lias uo lips, hence the lono- and 



OF CROCODILE. p ^ . . ^1 • 1 



close array oi grnmnig teeth is always 

 visible, imparting a very repulsive aspect to tlie 



