26o LIFE : OUTLINES OF GENERAL BIOLOGY 



Among reptiles the tongue is oftenest a touch and taste organ, 

 but it sometimes helps in catching the booty. The masterpiece is 

 the chameleon's, which may be seven inches in length — as long as 

 the body without counting the tail. A dead specimen with the 

 tongue out and the tail dangling looks as if it had a tail at both 

 ends, like the Irishman's elephant. The chameleon focuses first one 

 eye and then the other and, having reached with imperceptibly slow 

 movements the striking distance, it projects its tongue like a lasso. 

 The clubbed end is very sticky, and in a flash the moth is in the 

 reptile's mouth. 



It is interesting to watch a snake's tongue quickly and tre- 

 mulously passing out from the mouth and in again. It ends typically 

 in two delicate filaments. As in most lizards, its use is for touch and 

 taste, and it has nothing to do with the poison, which is squeezed 

 out along the groove on or actually within the fang-like teeth. 

 Snakes use their tongue in feeling their way and in testing their 

 food, but not in salivating their prey as used to be believed. In 

 crocodiles and turtles the tongue lies flat on the floor of the mouth, 

 and is not protrusible. 



Among birds the tongue suddenly attains to great plasticity of 

 form; in nearly related types it may be very difterent, apparently 

 in relation to the fact that the food is very varied. Thus in those 

 woodpeckers that feed mainly on sap, the tip of the comparatively 

 short tongue is beset with numerous hair-like processes forming a 

 kind of brush, and the sweet fluid ascends in the capillary spaces 

 between. But in those woodpeckers that are insectivorous the 

 tongue ends in spines, not in a brush, and the length is extraordinary. 

 In the common American "Flicker" the tongue can be shot out for 

 two or three inches beyond the tip of the beak, and it is connected 

 at the back of the mouth with two long, curved branches of bone 

 (the hyoid), which are continued upwards over the occiput of the 

 skull and then forwards into the right nostril! "So when this bird 

 stretches out its tongue the tips of the rear branches leave the 

 opening of the nose, and shoot around over the surface of the 

 skull until they have gone as far as possible." Even the bur- 

 rowing ants have not much chance when the woodpecker begins 

 to "flick" with its long, slender white tongue. Yet it is interest- 

 ing to notice that in most, if not all, birds the intrinsic muscles of 

 the tongue have disappeared. The organ is worked by muscles 

 outside itself. 



What contrasts there are: for instance, between the thread-like 

 tongue of the humming-bird, more or less split and frayed near the 

 tip, and the thick, fleshy tongue of the flamingo, deeply sunk in the 

 lower jaw and bordered with soft, tooth-shaped processes. The 

 toucan has a long, thin tongue, fringed like a feather; the cockatoo's 

 is like a fleshy club; the duck's is broad and intricately fringed in 



