ORDER CHELONIA. 39 



which are found there. Just in the same manner, under the 

 influence of anger, the human countenance becomes red or 

 livid. Fear produces paleness, cold, violet-colour, diffused 

 bile, yellowness, &c. In fact, the cameleon, and other chang- 

 ing reptiles, do by no means assume the tints of neighbouring- 

 objects, but according to the emotions of fear, anger, or love, 

 the want of food, heat or cold, or the greater or less degree 

 of respiration, they undergo these divers colourations. These 

 even become so varied, that it is not always easy to deter- 

 mine what is the natural colour of the animal. 



The reptiles with naked skin, such as the batracians, are 

 closed up in this covering, as in a sack. It adheres to the 

 flesh only toward the mouth, the eyes, the anus, and the 

 toes. These last are always without claws in the batra- 

 cians, the species of which order are also always destitute of 

 scales, and of osseous plates or carapaces. 



The reptiles possess three kinds of teeth, tortoises excepted, 

 which have in lieu of them semi-osseous and trenchant gums. 

 In some species these are crenulated. The teeth which are 

 observed in the lizards are pointed, like canines, and more or 

 less long according to the genera. The crocodiles have them 

 very numerous, and very long, through the entire extent of 

 the jaw. But we have already in another place entered 

 pretty fully into the dentition of these animals. 



The serpents have also sharp teeth in both jaws^ and, what 

 to them is peculiar in their class, teeth in the palatine arches, 

 like many of the fishes. These teeth are fixed, or implanted 

 in the bone, and not hollowed. There are many ranges of 

 them. In addition, the venomous serpents have attached to 

 the maxillary bones very sharp and long teeth, hollowed 

 like a funnel, from which they can distil a yellow poison into 

 the wound which they make. These teeth are called fangs. 

 In the very venomous species, they stand in the upper maxil- 



