THEIE NATUEE AND EFFECTS. IIB 



■die from oolubrine-poisoning between two and three 

 hours after the infliction of the bite, to thirty- two per 

 cent. 



It may be mentioned here, as bearing on the causes 

 of the differences of the poisons of the two tribes of 

 venomous snakes, that on the duct leading from the 

 poison-gland of the daboia, midway between the gland 

 and its termination at the fang, there is a second gland, 

 completely surrounding the duct, into which it empties. 

 This accessory gland is globular, and is exceedingly 

 vascular. No trace of this structure can be found in 

 the cobra. 



The exact significance of the differences between the 

 poisons of the viperine and colubrine snakes must rest 

 at present in obscurity. But it may be well to point 

 out some of the conditions in which the two groups 

 differ, and the possible uses of the poison apparatus. On 

 consideration, it will probably be admitted that as a 

 means of defence the poison would not be of any real 

 assistance. It is true that many animals — such as the 

 monkey — have the greatest dread of snakes ; but the 

 monkey could have no possible motive in molesting a 

 colTra, or a cobra in injuring a monkey. This dread, 

 therefore, can hardly be of service to the reptiles. But 

 one of the Indian snakes' chief enemies, the mongoose, 

 has no fear whatever of the poison, as anyone will 

 confess who has seen with what complete ease he seizes 

 the snake and crushes out first one and then the other 



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