ALIMENTARY CANAL OF REPTILES. 



439 



mouth, but is not prolonged freely beyond it; its back part 



appears to rise,, but this is due to the 298 



continuation of the membrane from the 



base of the tongue over a transverse 



cartilaginous plate, formed by the basi- 



hyal, which, abutting against the velum 



palati, ib. d, can close the back part 



of the mouth. So that, when the 



Crocodile holds submerged a drowning 



prey, the water traversing the mouth 



has no access to the glottis. 1 



The membrane covering the dorsurn 

 of the tongue is beset by mucous 

 crypts ; the 6 ceratoglossi ' divide into 

 fasciculi, which decussate across the 

 median line. 



A salivary apparatus is as little 

 specialised in Batrachians as in Fishes. 

 Mucous crypts upon the tongue or 

 palate subserve the need of lubricating 

 the quickly swallowed and unmasti- 

 cated food. In Lizards a series of 

 orifices of mucous crypts extend 

 along the lip-groove of both jaws. In 

 the Crocodile, besides the lingual fol- 



* o 



licles, there are groups of more com- 

 plex ones on each side, behind the 

 palato-nares, opening into the meshes 

 of the plicated faucial membrane. In 

 Chelonians there are groups of mucous 

 follicles below the tongue, representing 

 the sublingual glands of Mammals. 

 The labial glands are abundantly de- 

 veloped in Ophidians. The secretion 

 of the lacrymal glands is added to the 

 lubricating fluid of the mouth. The 

 poison-gland of venomous Serpents 

 may be regarded as a specially de- 

 veloped parotid, but will be described 

 in another section. In all Reptiles 

 the secretions entering the mouth are 

 rather mucous and mechanical in func- Mouth, g uiiet,and stomach, crocodile. 



1 xx. vol. iii. p. 72, prep. no. 1466, 



