974 TONGUE 



nerves (p. 627), together with glands, blood-vessels and the tegu- 

 mentary sheath, which last is composed of horny epidermal cells, 

 and is frequently frayed out on the margins or at the tip, in various 

 ways according to the use to which it is put, but mainly connected 

 with the mode of feeding. A similar if not identical modification 

 of the Tongue seems to have been brought about in Birds belonging 

 to widely -difl[erent groups from adaptation to the same circum- 

 stances ; but here we must restrict ourselves to a notice of the 

 more striking or aberrant types, only remarking that generalizations 

 as well as conclusions from the shape of the bill and from the 

 nature of the food are very unsafe. 



The Tongue is frequently small in Birds which have the bill, 

 mouth and gullet very large, so that bulky food can be swallowed 

 whole and quickly. In Felecanns and Sula, for instance, the free 

 part of the Tongue is reduced to a little nodule. A similar 

 diminution is apparent in the Eatitx and Crypturi, in some Sphenisci 

 and Tubinares, in Numenius, Ciconise, Ihididx} Cancroma, Bucerotidx, 

 Upupidse, Alcedinidx and Caprimulgidx. On the other hand the 

 most marked development of the organ is found in the Anseres and 

 Phcenicopterus. In the former it ends in a horny scoop, concave 

 above, convex beneath, while its sides are beset with a row or rows 

 of horny papillx like very short bristles or denticulations, which fit 

 more or less into the similarly-serrated edges of the rhamphotheca or 

 sheath of the bill ; but its upper surface is furnished with short 

 and soft papillse sometimes of velvety appearance. Along the 

 middle of the Tongue runs a furrow bordered on each side by a 

 horny ridge, beset more or less thickly with hard papillss which aid 

 in swallowing the food. On the under side of the root lies a pair 

 of cushion-like swellings, filled with fat. In most Birds-of-Prey the 

 Tongue is thick, soft and spoon-shaped, but short ; in the Pici 

 (Woodpecker) it is long, round, narrow, pointed at the end and, 

 in the most insectivorous forms of the group, beset with spines or 

 hooks directed backward. The elaborate apparatus already de- 

 scribed (pp. 452, 619) serves to protrude the organ, by means of 

 which the bird is able to stir up and, in Mr. Lucas's neat phrase 



cannot serve as organs of taste though they may act as organs of touch. More- 

 over, corpuscles of the same kind are generally distributed not only in the palate 

 and bill (as in the Snipes for instance, and in the nail-like tip of the beak in 

 Anseres), but also in great numbers in different parts of the body — as near the 

 roots of the contour-feathers, especially the rectrices and remiges, in the cloaca, 

 in the mesentery and, last though not least, in the joints of the skeleton, but 

 above all in the periosteum of the tibia. However, " taste" is one of the diffuse 

 senses. 



1 The extraordinary reduction of the Tongue in Ihis and Platalea induced 

 Nitzsch {Pterylographie, p. 193) to combine those genera in one group as 

 Hemiglottides. 



