ORGANS OF TASTE AND TOUCH. 159 



within the mouth, lodged in a deep groove of the palate, and enclosed 

 within a long sheath. 



The Lingual bone of the Reptilia, whifch supports the tongue, 

 exhibits great diversities, and in the Ichthyodea it resembles most 

 that of Fishes. It consists in them of one or two middle azygos 

 pieces lying behind each other, and supporting in front a broad 

 cartilaginous plate. A pair of lateral pieces represent the anterior 

 cornua, and serve to attach the lingual bone, through the interven- 

 tion of ligaments, to the skull. Posteriorly, the single piece coa- 

 lesces with the superior pieces of the branchial arches, which rep- 

 resent in some respects the posterior cornua. In the Batrachia, 

 c. g., the Frog, a similar structure is met with in their tadpole or 

 larval state. At a later period of existence, after the disappear- 

 ance of their branchiae, the parts blend more together, and there 

 remain a middle piece or body, a pair of anterior flattened, and a 

 pair of lesser posterior, cornua. In the Chelonia, the lingual bone 

 is very different, and consists frequently of a great number of 

 pieces, amounting even to 20 in Trionyx. A single median body is 

 however invariably present, and two pairs of cornua, the posterior 

 of which usually consist of several pieces ; occasionally, a very 

 small third pair of cornua is appended to the body in front, as in 

 Emys. The lingual bone of the Ophidia is very simple, for here 

 the body is entirely wanting, and there are present only the ante- 

 rior cornua, as a pair of long cartilaginous filaments, connected in 

 front by ligaments. In the Lizards a very delicate cartilaginous 

 filament (appendix styloidea Losana) unites the small body of the 

 lingual bone to the skull. The structure of the body of the bone 

 in the Crocodile is directly the reverse, being flat, very large and 

 broad, with only the posterior pair of cornua occurring as appen- 

 dages. In the rest of the Sauria the middle portion or body is pro- 

 longed into a fine cartilage which penetrates the substance of the 

 tongue ; two pairs of cornua are found, whereof the anterior are by 

 far the longest, and frequently present several curves ; the posterior 

 pair are more simple, regular in form, and always consist of bone. 

 Occasionally, as in the Lizards proper, the body is slit posteriorly 

 into two crura, or processes, which correspond to the single process 

 in Birds. In Ophisaurus and Anguis the anterior cornua are entirely 

 cartilaginous, and the body is very small in Amphisboena, so that these 

 structures conduct at once to those already described as existing in 

 the Serpents. 



As regards the Muscles, the tongue is furnished with a protrac- 



