ORDER OPHIDIA. 371 



had fewer than half a dozen of these vipers who burnt 

 themselves to death by approaching the embers"), Mr. Bruce 

 proceeds to give so accurate a description of the animal as 

 evidently proves his great familiarity with it. He then 

 goes on : — 



"^ The poison is very copious for so small a creature : it 

 is fully as large as a drop of laudanum, dropt from a vial 

 by a careful hand. Viewed through a glass, it appears not 

 perfectly transparent or pellucid. I should imagine it hath 

 other reservoirs than the bag under the tooth, for I com- 

 pelled it to scratch eighteen pigeons upon the thigh as quickly 

 as possible, and all died nearly in the same interval of time ; 

 hut I confess the danger attending the dissection of the 

 head of this creature made me so cautious that any obser- 

 vation I should make upon these parts would he less to he 

 depended upon.'''' 



" I kept two of these last mentioned creatures (the ce- 

 rastes) in a glass jar, such as is used for keeping sweetmeats 

 in, for two years, without having given them any food — -they 

 did not sleep, that I observed, in winter, but cast their skins 

 the last days of April. The cerastes moves with great 

 rapidity, and in all directions, forward, backward, and side- 

 ways. When he inclines to surprise any one who is too far 

 from him, he creeps with his side towards the person, and 

 his head averted, till judging his distance, he turns round, 

 springs upon him, and fastens upon the part next to him ; 

 for it is not true what is said that the cerastes does not leap 

 or spring. I saw one of them at Cairo, in the house of 

 Julian and Rosa, crawl up the side of a box, in which there 

 were many, and there lie still, as if hiding himself, till one 

 of the people who brought them to us came near him, and 

 though in a very disadvantageous posture, sticking as it 

 were perpendicular to the side of the box, he leaped near the 

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



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