﻿EXTERNAL ANATOMY. TONGUE. 51 



action is much assisted by the formation of the root of 

 the tongue, as it is usually called, or more properly the 

 os hyoides, or forked bones by which it is attached to the 

 mouth. These bones are greatly lengthened, and are 

 compactly curved round the skull, having on each side a 

 little sac or reservoir of a particular secretion which 

 serves to lubricate the muscles ; just as we apply grease 

 to the wheels of a carriage. Now, the use of this com- 

 plicated structure, — which does not, however, as in the 

 duck, imply any unusual sensibility of touch, — -is inti- 

 mately and vitally connected with the habits of the bird. 

 Its bill, indeed, is remarkably powerful, and capable of 

 breaking into the strongest wood; but there its powers 

 cease : its tip is made for splitting, not for piercing; and 

 it has no teeth or notch by which it could firmly grasp 

 a struggling insect. No sooner, therefore, has the wood- 

 pecker, by breaking away the external bark with pow- 

 erful strokes of the bill, laid open the retreat of the insect 

 beneath, than it suddenly darts out its tongue, spears its 

 prey, and instantly brings the luckless insect to its mouth. 

 Tongues of this structure are not entirely confined to the 

 family of woodpeckers, under which we include the wry- 

 neck, but we detected an example among the Brazilian 

 creepers, forming the genus Dendrocolaptes, whose tongues 

 have been supposed by all ornithologists to be similar to 

 that of the common European creeper; that is, thin, simply 

 pointed, and not extensible. We shall now describe two 

 other modifications of this member, very different from the 

 last, but which are also capable of being considerably 

 elongated. The first of these is seen in the humming birds 

 ( Trochilidce) ; the second in the honeysuckers (Melipha- 

 gidce.) It has generally been supposed that the two long 

 filaments into which the tongue of the humming bird is 

 divided were tubular, by which construction they were 

 enabled to suck up from the nectary of flowers the 

 natural honey therein contained. But this is altogether 

 erroneous. So far back as the year 1817, we detected this 

 error in dissecting the humming birds of Brazil ; and we 

 have often announced the fact, that the food of these 

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