STRUCTURE OF THE TONGUE IN REPTILES. 685 



muscles of the abdomen become developed ; and ultimately those of the 

 limbs are superadded as those members successively make their appear- 

 ance, the muscles of the shoulder and pelvic region being first recog- 

 nizable, and subsequently those of the legs and feet. In the meantime, 

 as the abdominal muscles and those of the extremities become gradu- 

 ally perfected, those peculiar to the fish-state are rapidly removed : the 

 broad tail becomes atrophied and absorbed, diminishing in length nearly 

 at the rate of a line a day ; the flaky lateral muscles of the caudal 

 region disappear altogether ; and, moreover, the entire muscular appa- 

 ratus of the branchial and hyoid systems is altered as the character of 

 the respiratory organs becomes changed, in a manner to be explained 

 hereafter, from the aquatic to the aerial condition. 



(1914.) As Reptiles, for the most part, must from necessity swallow 

 their prey entire, organs of taste would be scarcely more useful to them 

 than to the fishes described in the last chapter ; and we are therefore 

 not at all surprised to find the tongue in almost every family appro- 

 priated to a totally different use, and not unfrequently converted into an 

 apparatus of prehension, whereby the food is seized and conveyed into 

 the mouth. 



(1915.) In the Batrachoid Amphibia, for instance, we have a remark- 

 able example of this provision. The Frog and the Toad, notwithstand- 

 ing their slow and clumsy movements, are destined to feed upon insects, 

 and consequently must be provided with some instrument by which such 

 active prey may be caught. The organ provided for this purpose is the 

 tongue, which, by a slight modification in its structure, becomes changed 

 into a prehensile forceps admirably adapted to such an office. The 

 tongue of the Frog, instead of presenting the usual arrangement, is 

 found to be fixed to the symphysis of the lower jaw, and folded back 

 upon itself, so that its point, which is free and bifid, is lodged in the 

 throat. Thus provided, the Frog is enabled to seize its victim with the 

 greatest ease. No sooner does a fly approach sufficiently near, than this 

 living forceps is rapidly everted ; and the insect, being seized by its 

 furcate extremity, is as speedily brought between the jaws of its de- 

 stroyer. The teeth of the Batrachia very much resemble those of the 

 generality of fishes, being simple points soldered to the surface of the 

 jaws, but not implanted in sockets sufficient to give a secure hold of 

 their food, but quite unadapted to mastication. 



(1916.) The Chameleon is another curious example of a reptile obliged 

 to employ its tongue in securing insect prey. The Chameleon is arboreal 

 in its habits : its feet, cleft as it were into two portions, firmly grasp the 

 boughs upon which it climbs ; while its well-known power of changing 

 the colour of its skin, so as to imitate that of the branches around it, 

 efficiently conceals it from observation. The tongue of this creature, 

 when extended, is as long as its whole body, and is terminated by a club- 

 shaped extremity smeared over with a viscid secretion : when an insect 



