The tongue of the parrot, although its substance is not so fleshy, has some resemblance to that of man, and it is probable that this is one of the circumstances enabling these birds to imitate the human voice with so much facility. In the family of the toucans and some others, the tongue, without being extensible, is fully as long as the largely developed bill, and, moreover, its sides are fringed like those of a feather. A tongue of this description may probably be endowed with some delicacy of taste, enabling these birds to appreciate the flavour of the fruits on which they feed. Birds of the duck family have the largest tongues. Owing to its fleshy appearance it more nearly resembles the human tongue than even that of the parrot. Birds of this family discriminate their food not by sight, but by the delicate sense of touch with which their tongue is endowed. They thrust their bill into the mud, and from the mouthful thus obtained select, by means of their tongue alone, whatever is fit for food, rejecting the rest. The smallest tongues are found in the night-jars and swallows, two groups which at the same time are distinguished by having the largest mouths in proportion to the size of their bodies; and in this case the design is equally apparent. These birds feed upon living insects captured during their rapid flight, and immediately swallowed whole; taste is out of the question. A large tongue would only be in the way, and it is therefore reduced to a mere rudiment. [Illustration: Fig. 9.--THE THROAT OF A FOWL, SHOWING THE PARTS _in situ_. _a_, the Lower Mandible; _c_, the Tongue; _h_, _m_, interior of the Gullet; _i_, the Upper Larynx.]