io6 NATURAL HISTORY OF SELBORNE 



ably short, between which and the anus lay the crop, or 

 craw, and immediately behind that the bowels against the 

 back-bone. 



It must be allowed, as this anatomist observes, that 

 the crop placed just upon the bowels must, especially when 

 full, be in a very uneasy situation during the business of 

 incubation ; yet the test will be 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 goatsucker, as soon as oppor- 

 tunity offered : 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 it's 

 habit and shape, we suspected might resemble the cuckoo 

 in it's internal construction. Nor were our suspicions ill- 

 grounded ; for, upon the dissection, the crop, or craw, 1 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 phalcence, 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 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? 



1 Neither Herissant nor Gilbert White appears to have had any clear notion of 

 the distinction between the "crop or craw" and the stomach. It will be noticed 

 that White uses the terms "crop or craw" and stomach indifferently, or as 

 synonyms of the same organ. As a matter of fact the structure which so much 

 troubled these gentlemen is really the stomach. This, it is true, in its backward 

 position is somewhat abnormal, but as it is precisely similarly situated in the 

 Nightjar as White himself pointed out and many other birds, this can have no 

 share in causing the parasitic habits of the Cuckoo. Moreover, the parasitic 

 Molothrus has the stomach normally placed with regard to the sternum. [W.P. P.] 



2 There is nothing in the anatomical structure of the Cuckoo to prevent its per- 

 forming all the duties of incubation. Parasitism is extended over a considerable 



