THE CUCKOO. 199 



LETTER LXXII. 



TO THE HON. DAINES BARRINGTON. 



SELBORNE, April 3, 1776. 



DEAR SIR, Monsieur Herissant, a French anatomist, seems 

 persuaded that he has discovered the reason why cuckoos do 

 not hatch their own eggs ; the impediment, he supposes, arises 

 from the internal structure of their parts, which incapacitates 

 them for incubation. According to this gentleman, the crop, 

 or craw, of a cuckoo, does not lie before the sternum at the 

 bottom of the neck, as in the gallmcB, columbce, &c. but imme- 

 diately behind it, on and over the bowels, so as to make a large 

 protuberance in the belly.* 



Induced by this assertion, we procured a cuckoo ; and, 

 cutting open the breast-bone, and exposing the intestines to 

 sight, found the crop lying as mentioned above. This stomach 

 was large and round, and stuffed hard, like a pin-cushion, with 

 food, which, upon nice examination, we found to consist of 

 various insects ; such "as small scarabs, spiders, and dragon- 

 flies ; the last of which we have seen cuckoos catching on 

 the wing, as they were just emerging out of the aurelia state. 

 Among this farrago also were to be seen maggots, and many 

 seeds, which belonged either to gooseberries, currants, cran- 

 berries, or some such fruit ; so that these birds apparently 

 subsist on insects and fruits ; nor was there the least appear- 

 ance of bones, feathers, or fur, to support the idle notion of 

 their being birds of prey, f 



The sternum in this bird seemed to us to be remarkably 

 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 below 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. 



* Histoire de F Academic Roy ale, 1752. 



f Sir William Jardine says, that when cuckoos have fed much on some of 

 the large hairy caterpillars so common on the northern moors, the stomach 

 becomes coated with the short hairs, which may have given rise to the 

 opinion that they are predatory. But has not Sir William mistaken the 

 fibrous structure of the stomach for these hairs ? Its American congeners, 

 the yellow-billed cuckoo, and the black-billed cuckoo, rob birds of their 

 effgs ; and the latter feeds on fresh water shell-fish. ED. 



