TONGUE. 



Fig. 760. 



1145 



Comparative anatomy of the hyoid apparatus. (After Geoff roy and Owen.) 



A, Fish (Cod). B, Reptile (Frog : 1, tadpole ; 2, adult). C, D, Bird (C, Crane; D, Woodpecker). 



E, Mammal (Horse). 



ime ossified, and, together with the cerato- 

 lyal, coalesce with the basi-hyal. As in their 



rious condition they subserved to respira- 

 tion, so now they do the same as they 

 jfore supported the branchiae, so now they 

 support the trachea and larynx : they may be 

 always recognized by this relation, they 

 always embrace the commencement of the 

 air-passages in their fork, being especially 

 connected with the first segment of the carti- 

 laginous framework of those passages, namely, 

 the thyroid cartilage ; the universality of this 

 relation has induced Professor Owen to name 

 them, in air-breathing vertebrata, tliyro-hyals 

 (fig. 760. C, D, E, kb, cb). 



In birds (fig.lQQ. C and D), the elements of 

 the true hyoid arch are either rudimentary 

 or suppressed, while the hypo- and cerato- 

 branchials (h b y c b) are enormously deve- 



loped. The basi-hyal (b h) is generally 

 elongated proportionately to the shape of the 

 tongue, and to its anterior extremity is usually 

 attached a glosso-hyal (g h\ to its posterior a 

 stiliform uro-hyal (u //) which is prolonged be- 

 neath the trachea. In C, which represents the 

 hyoid apparatus of the crane (Grus cinerea), 

 the glosso-hyal is seen to be wanting, and two 

 rudimentary cerato-hyals (c Ji), lesser cornua, 

 to be attached to the anterior extremity of 

 the basi-hyal. In D is represented the hyoid 

 apparatus of the woodpecker (Picus); the 

 parts are seen to be very long and slender, 

 furnishing the means for the lengthened pro- 

 trusion of the tongue in pursuit of food. All 

 the bones are seen to be linear; there is a 

 long basi-hyal (b h), surmounted by an arrow- 

 shaped glosso-hyal (g h), while two slender 

 hypo-branchials*(/* b,) (greater cornua) are 



