201 



THE NATURAL HISTORY 



[LETT. 



tlie test will l>e to examine whether birds that are actually 

 known to sit for certain are not formed in a similar manner. 

 This inquiry I proposed to myself to make 'with a fern-owl, or 

 goat-sucker, as soon as opportunity ottered : because, if their 

 formation proves the same, the reason for incapacity in the 

 cuckoo will be allowed to have been taken up somewhat 

 hastily. 



Not long after a fern-owl was procured, which, from its habit 

 and shape, we suspected might resemble the cuckoo in its 

 internal construction. Nor were our suspicions ill-grounded ; 

 for upon dissection, the crop, or craw, also lay behind the 

 sternum, immediately on the viscera, between them and the 

 skin of the belly. It was bulky, and stuffed hard with large 

 jihalcciuK, moths of several sorts, and their eggs, which no doubt 

 had been forced out of those insects by the action of swallowing. 



Now as it appears that this bird, which is so well known to 

 practise incubation, is formed in a similar manner with cuckoos, 

 Monsieur Herissant's conjecture, that cuckoos are incapable of 

 incubation from the disposition of their intestines, 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 

 cfinorus. 



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

 respect to formation ; and, as far as 1 can recollect, with the 

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

 that are not granivorous. 



SKLBOKXE, April 3, 1776. 



COAT-SITKKR'S <;<;. 



