ANIMAL KINGDOM. 



additional jaw-bone already described, and in order that the 

 mass may not slip out during any momentary relaxation 

 of the awful living rope, the teeth are set so that they 

 bend backwards, and thus they prevent the body moving 

 in an opposite direction. Boas have two hook-like clav/s, 

 sheathed with horn, each terminated by a sort of spur, 

 which seem like rudiments of hind limbs ; these assist the 

 animal in moving along. 



The Harmless Snakes are very numerous. One of 

 them, the common Ringed Snake (Fig. 66), is often found 

 in our own country. It lives in low damp meadows, and 

 in the vicinity of water ; it feeds principally on frogs, 

 mice, shrews, and small birds, and can swim well. It is 

 easily tamed, and is said to become much attached to the 

 person it lives with. In winter it becomes torpid, having 

 previously taken shelter in some secluded place, where a 

 great number will often collect. Dr. Carpenter mentions 

 an instance within his own knowledge of 1,300 having 

 been found in an old lime-kiln. 



The last family of serpents are called the Double 

 Walkers, from the circumstance of their moving equally 

 well with either end foremost. They feed on insects and 

 other very small animals, and are natives of the tropical 

 regions. 



Amphibious* Reptiles are such as by their peculiar 

 organisation are enabled to live on land or in water ; and 

 thus they breathe by means of lungs when on land, and 

 of gills when in water. Some retain their branchicc, 

 or gills, and their lungs at the same time throughout their 

 whole life, whilst others lose them at a particular period. 

 Amongst amphibious reptiles with permanent gills may 

 be mentioned the snake-like Proteus (Fig. 70). This 

 animal is something like an eel in shape ; its gills arc not 



* A HI f his, both ; bios, to live living in two elements. 



