574 SNAKES. 



with ' unscientific imaginations ; ' but having its head in the 

 centre of such a coil, the snake would not easily reach its 

 object. Often the coils are like those of 'Totsey' when 

 taking her choice of a bird, having loose folds near the 

 head, which is sXwdiys forward in readiness for the attack. 



Excellent opportunities of observing the relative venoms 

 present themselves in zoological collections — not only the 

 degrees of poison seen in the different serpents, but the 

 effects produced by one serpent at different times. Of those 

 species when in full vigour there is no doubt but that the 

 South American rattlesnake {Crotalus horridns) is one of the 

 most virulent. Sometimes this species will strike at a young 

 rabbit or a guinea-pig, and death is almost instantaneous. 

 One such instance was observed when a rattlesnake struck 

 a guinea-pig on the head, the little animal falling as if shot, 

 and in such a flash of time that Holland examined it to 

 ascertain the cause, and * its brains had turned quite green 

 directly.' 



*A new rattlesnake' was introduced in the autumn of 

 1873. Not new to science, but this, I regret to find, is 

 all that my notebook records in heading some observations 

 made September 26th of that year, ' a very warm day ' 

 for the season. A guinea-pig was put into the cage, when 

 the snake (I think it was Crotalus diirisstis) approached its 

 head closely and stealthily till quite near to the little animal, 

 shrinking back at the slightest movement on the part of the 

 guinea-pig, which sat staring and blinking in a corner. Each 

 time the snake recoiled, even at a blink, it kept its eyes fixed 

 in alarm on the piggy, who stupidly returned the gaze, not 

 knowing what to make of the snake or of the people so 



