THE COMMON VIPER OR ADDER. 



509 



The Cerastes has, according to Bruce, an awkward habit of crawl- 

 ing until it is alongside of the creature whom it is about to attack, 

 and then making a sidelong leap at its victim. He relates an in- 

 stance where he saw a Cerastes perform a feat which was certainly 

 curious : 



" I saw one of 

 them at Cairo 

 crawl up the 

 side of a box 

 in which there 

 were many, and 

 there lie still, as 

 if hiding him- 

 self, till one of 

 the people who 

 brought them to 

 us came near him. 

 and, though in 

 a very disadvan- 

 tageous position, 

 sticking, as it 

 were, perpendic- 

 ularly to the side 



of the box, he The Cerastes or Horned Viper (Ceirtstea Hasselquistii). 

 leaped near the 



distance of three feet, and fastened between the man's fore finger and 

 thumb, so as to bring the blood." 



The Cerastes usually lives in the driest and hottest parts of Northern 

 Africa, and lies half buried in the sand until its prey should come 

 within reach. Like many serpents, it can endure a very prolonged 

 frost without appearing to suffer any inconvenience ; those kept by 

 Bruce lived for two years in a glass jar without partaking of food, 

 and seemed perfectly brisk and lively, casting their skins as usual, and 

 not becoming torpid even during the winter. 



The color of the Cerastes is pale brownish white, covered irregularly 

 with brown spots. Its length is about two feet. 



The common Viper, or Adder, is very well known in many parts 

 of England, but in some localities is very plentiful, while in others it 

 is never seen from one year's end to another. 



Many persons mistake the common grass snake for the Viper, and 

 dread it accordingly. They may, however, always distinguish the 

 poisonous reptile from the innocuous by the chain of dark spots that 

 runs along the spine and forms an unfailing guide to its identification. 

 Fortunately for ourselves, it is the only poiscmous reptile inhabiting 



