312 GENERAL ORNITHOLOGY part ii 



the geniohyoid (Fig. 101, i, d) is another, which passes like the first 

 from the mandibular to the hyoid bone ; a third is the stylohyoid 

 («). The floor in some cases forms a pouch, which, as in the peli- 

 can, is of great extent and susceptible of enormous dilatation. 



The handler of the mouth, or lingual organ, is the tongue, which 

 answers the same purpose as in other creatures : it is tactile, to some 

 extent gustatory, sometimes prehensile, nearly always manipulatory. 

 In some birds, as the pelican and ibis, and also the kingfisher, it is 

 very slightly developed, — scarcely more than a pad at the bottom 

 of the mouth, enjoying the most limited motion or other function. 

 In some birds, as the parrot and duck tribes, and also the flamingo, 

 the tongue is large, thick, and fleshy, quite filling the mouth. In 

 the first-named of these, it is dexterously manipulatory ; the morsel 

 of food is managed between the tongue and upper beak ; the tactile 

 certainly, and perhaps'the gustatory sense is highly developed ; and 

 the fleshiness of the tongue may affect that power of articulate speech 

 for which some parrots are justly noted. In the Lamellirostres just 

 mentioned the tongue has lateral processes corresponding to the 

 denticulations of the beak, and the under surface is horny at the 

 end, like a human finger-nail. In the woodpeckers (Figs. 73, 74) 

 the tongue itself (glossohyal part of the hyoid) is reduced to a 

 slight horny and spiny tip of the lingual apparatus ; but other parts 

 of that mechanism are so extraordinarily developed that the "tongue" 

 appears as a lumbriciform (worm-like), spear-headed organ usually 

 capable of great protrusion from the mouth, and therefore acting as 

 a prehensile instrument, being bedewed for that purpose with tena- 

 cious saliva from the great salivary glands ; while it is actuated in 

 protrusion and retraction by specially developed muscles. In the 

 snipe and many other long slender-billed waders, the tongue is 

 similarly slender, but not protrusible. The long narrow tongue of the 

 toucans {ElMmphastidce) is beset with slender processes, so that it 

 seems feathery. The tongue of .the humming-bird is very singular. 

 These and other interesting extremes aside, the ordinary style of a 

 bird's tongue is flat, narrow, more or less sagittate or lanceolate, 

 and tipped or sheathed in horn, commonly with lateral backward 

 processes like the barbs of an arrow-head, — the whole glossal struc- 

 ture upborne pretty distinctly upon the end of the basihyal bone. 

 (See Fig. 101, where i, a, is such an ordinary tongue, and ^, a-f, is its 

 whole skeleton.) Such horny tongues are commonly bifid at the 

 extreme tip or there variously lacerate, or laciniate, or thready, — 

 and even the fleshy tongue of some parrots, as the lories, is brushy 

 at the end. The bony foundation of the tongue is the composite 

 hyoid bone, already often mentioned ; the free lingual part proper 

 is based upon the glossohyal and its terminal cartilage ; the roots 

 curve more or less extensively about the base or more of the skull. 



