2 72 CROCODILES AND SNAKES 



and are secured by the legs in the meanwhile. Sometimes nets are 

 used to catch the smaller ones, and harpooning is also resorted to. 

 But the prime object is to capture the turtle alive for the markets of 

 the great towns of the world. 



The Geckos are very numerous in warmer countries, and such 

 is their familiarity with man that they do not hesitate to introduce 

 themselves into his habitations, where they render an all-important 

 service by devouring flies, spiders and other insects. They themselves 

 are kept within limits by the birds of prey, such as the owl and the 

 hawk, which feed upon them greedily. 



These lizards are enabled to glide along ceilings or steep walls, 

 owing to the construction of the soles of their broad feet. All the 

 toes are considerably broadened at the edges, and their under surface 

 is divided into a number of scales or layers, from which exudes a 

 sticky iluid. They are also provided with sharp, crooked, retractile 

 claws, like those of a cat, and these assist them greatly in climbing 

 trees. During the day the geckos generally lurk in some dark corner 

 or crevice ; but at dusk they sally forth in search of prey, running along 

 the stee])est walls with wonderful swiftness, and venting a shrill, (|uick 

 noise l)y smacking their tongue against the ])alate. 



The Snakes are a very large and important order of reptiles. 

 They mav be divided into two groups, the one consisting of those 

 which are poisonous, and tlie other of those which are not. \W far the 

 greater number of snakes have no limbs at all, while those members 

 are so small in the few which jjossess them that they are not of the 

 least use in enabling their owner either to glide or to climb. And so 

 snakes move i^rincipally by means of their scales, which overlap one 

 another, and which can be raised at will so as to take a firm hold of 

 the ground. 



The first necessity for a poisonous snake is the poison. This is 

 always found in two glands in the head, corresponding to the saliva 

 glands in higher animals. Fatal though it is in its efifects when intro- 

 duced into the blood of the victim, this poison is quite harmless if 

 swallowed, and you might drink the poison of a viper without being 

 injured by it at all. 



Many people think that the forked tongue of a snake is poisonous, 



