REPTILES. 211 



from the mouth ; the adhesive mucus, with which the surface of 

 the tongue is covered, causes the little worms and insects that are 

 touched by it to adhere. A cylindrical tongue, capable of great 

 extension, which is shot from the mouth with much rapidity, is the 

 weapon by which the chameleon overpowers his prey. In most of 

 the saurians however, and in the serpents, the tongue does not serve 

 for seizing the food, but is rather an organ of feeling or tact, of 

 which these animals avail themselves almost as insects do of their 

 feelers and antennae. 



Salivary glands, which are missing in fishes, are here also often 

 wanting, as in the batrachians, or are only slightly developed. 

 In many lacertine animals and in serpents small glands are situ- 

 ated along the jaws, or in the lips, which give out the fluid secreted 

 by them through numerous apertures. Often also there is a sub- 

 lingual salivary gland, in serpents and lizards, as well as in land 

 and fresh-water tortoises 1 . The poison-glands of serpents we shall 

 describe subsequently. 



The oesophagus is longer than in fishes and more clearly 

 distinguishable from the stomach 2 . In the salamanders, however, 

 the oesophagus passes insensibly into the elongated stomach, 

 which becomes narrower near the pylorus, and forms a fold before 

 it terminates in the duodenum. The stomach of serpents is only 

 slightly wider than the rest of the intestinal tube; it is with- 

 out curvature, and has thicker walls than the oesophagus; its 

 inner surface presents longitudinal folds. These occur also in 

 the stomach of tortoises, where also are seen numbers of small 

 apertures of glands that lie in its walls. The oesophagus of 

 turtles is beset on the inside with large conical papillae placed close 

 together, which have a horny envelope (epithelium), and whose 

 points are turned backwards ; in the rest of the tortoises they are 

 wanting. In the crocodiles the stomach is round and the muscu- 

 lar coat thick ; it has a great resemblance to the stomach of birds 3 . 



1 See this gland in the European fresh-water tortoise, where it has many ducts 

 that perforate the tongue, figured by L. H. BOJANUS in his eminent Anatome Te&tu- 

 dinis Europece, 18191821, folio. Tab. 26, figs. 140, 141 H. 



2 On the deglutition of reptiles compare DUGES Ann. des Sciences not. XII. 1827, 

 PP- 337395, PL 48. 



3 The stomach of Crocodilus acutus is very beautifully figured in the Catalogue of 

 the physiological series of comparative Anatomy in the Museum of the College of Surgeons. 

 London, 1833, I. PI. 9, p. 266. 



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