NOTES FROM THE ZOOLOGICAL GARDENS. siS 



close to him. By and by the snake, regaining courage, 

 again ventured nearer, and again when nearly close started 

 back at a slight movement of the guinea-pig. Three times 

 a similar approach was made before the snake ventured to 

 strike, betraying its extreme caution and timidity. As soon 

 as struck, the guinea-pig was convulsed, and falling on its 

 side was dead in three minutes. 



Rats do not succumb to the poison nearly so quickly as 

 rabbits, guinea-pigs, and birds. 



Another guinea-pig struck by a rattlesnake immediately 

 fell over on its side, and died, panting hard, in about three 

 minutes. One could not discern the precise moment of its 

 last gasp ; but in this case there were no convulsive jerkings 

 of the limbs. 



The rattlesnakes always strike and then recede quickly, 

 keeping a stealthy watch over their prey until it is perfectly 

 still, often much longer. Puff adders and some others of 

 the African vipers, on the contrary, retain their hold after 

 biting. Cobras sometimes strike and retain their hold, and 

 sometimes let the prey go and wait for it to die. On a small 

 creature the effect of Puff-adder venom is instantaneous ; 

 and a remarkable difference is observable between the effect 

 on a timid victim and on a rat. One of these adders ate a 

 sparrow alive August 20, 1874, that is, struck and held it, 

 swallowing it so quickly that it had not time to die. A 

 sparrow Is, however, a very small prey for so large a serpent. 

 Another Puff adder, about to cast its coat, bit a guinea-pig, 

 which was rapidly convulsed, as with spasms, accompanied 

 by sharp jerkings of the limbs for nearly five minutes, when 

 it became motionless. In this case the charge of venom 



