OF SELBORNE. 197 



cuckoos, Monsieur Herissant 's conjecture, that cuckoos are 

 incapable of incubation from the disposition of their intes- 

 tines, seems to fall to the ground : and we are still at a loss 

 for the cause of that strange and singular peculiarity in the 

 instance of the cuculus canorus. 



We found the case to be the same with the ring-tail hawk, 

 in respect to formation ; and, as far as I can recollect, with 

 the swift ; and probably it is so with many more sorts of birds 

 that are not granivorous. 



I am, &c. 



LETTER XXXI. 



TO THE SAME. 



Selborne, April 29, 1776. 



DEAR SIR, 



ON August the 4th ; 1775, we surprised a large viper, which 

 seemed very heavy and bloated, as it lay in the grass basking 

 in the sun. When we came to cut it up, we found that the 

 abdomen was crowded with young, fifteen in number ; the 

 shortest of which measured full seven inches, and were about 

 the size of full-grown earth-worms. This little fry issued 

 into the world with the true viper-spirit about them, shewing 

 great alertness as soon as disengaged from the belly of the 

 dam : they twisted and wriggled about, and set themselves 

 up, and gaped very wide when touched with a stick, shewing 

 manifest tokens of menace and defiance, though as yet they 

 had no manner of fangs that we could find, even with the 

 help of our glasses. 



To a thinking mind nothing is more wonderful than that 

 early instinct which impresses young animals with the notion 

 of the situation of their natural weapons, and of using them 

 properly in their own defence, even before those weapons 

 subsist or are formed. Thus a young cock will spar at his 

 adversary before his spurs are grown ; and a calf or a lamb 

 will push with their heads before their horns are sprouted. 



