THE ANIMAL KINGDOM. 



Venomous Serpents, amongst which we find the 

 Rattlesnake, the Cobra, the Asp, the Viper, &c. 

 They inflict their deadly bite by means of two large fanrs 

 (b, Fig. 67), which are connected with the poison gland. 

 When in a state of quietude, these fangs are bent back - 

 ward against the roof of the mouth ; but when the animal 

 is about striking its prey they are erected, and in this act 

 the muscles (d) which elevate the lower jaw at the same 

 time compress the poison gland (e), forcing the dead'/ 

 fluid down a channel in the side of the tooth, 

 and it thus at once enters the wound inflicted. 

 Serpents are able to swallow prey which is 

 larger than the size of their mouth might seem 

 to admit of; this is owing to an additional bone, 

 called the Tympanic bone (a), the action of which 

 you will understand on referring to the draw- 

 ing (Fig. 68). By this means the width of the 

 mouth is immensely increased ; the animal they 

 have killed is gradually swallowed ; and after 

 their meal, the serpents remain for some time 

 in a torpid state. The " rattle " of the Rattle-* 

 snake (Fig. 69) consists of a number of horny 

 rings, loosely put together, which rattle against each other 

 with the slightest movement of the animal. 



The Boa family comprises the largest of all serpents, 

 viz., the Anaconda. Boas are not venomous ; but this 

 is scarcely any advantage to the poor animal which, by 

 adverse fate, has fallen in the way of the giant reptile. 

 It hangs by the end of its tail from a branch of a tree, 

 overhanging some river, and as a quadruped comes to 

 drink it instantly darts down on its prey, coils around 

 it, and literally squeezes the life out of its body hence its 

 name, boa "constrictor." It then loosens its dreadful 

 embrace, and again gathering around the body, it forces 

 the head down its mouth, extended by means of the 



H 



Fig. 69. 



