CONCERNING SERPENTS. 



269 



instincts peculiar to themselves, which are directly related to the 

 necessities of their being ; but we are not aware that they display 

 great sagacity, cunning, or wisdom. They arc not fertile in devices, 

 not especially artful, and the extreme simplicity and smallness of 

 their brain indicate their low mejital powers. 



The entire tribe of serpents for the purposes of this paper may be 

 divided into the venomous and non-venomous species. Of the non- 

 venomous, we will pass, with one or two remarks, the interesting 

 families of double walkers, and slow or blind worms (Fig. 14), types 

 which are structurally intermediate between true serpents and lizards. 

 The first of these derives its name from the fact that it can progress 



Fig. 11. 



Feb de Lance. 



with facility forward or backward; the second from the erroneous 

 notion that it has no eyes. To this class belong the curious glass- 

 snakes, so named from their fragility. Other non-venomous serpents 

 comprise the inoffensive and harmless, and some of the most terrible 

 species. Of these we have noticed the gigantic rock-snake or python 

 of India, which attains a length of 30 feet. The Natal rock-snake is 

 found 25 feet long. Of equal size is the boa-constrictor of tropical 

 America, formerly an object of worship. The anaconda, or water- 

 serpent, which frequents the rivers of Brazil, and watches for its prey 

 along their banks, is sometimes more than 25 feet long. These are 



