LXXII.] OF SELBORNE. 
LETTER LXXII. 
TO THE HONOURABLE DAINES BARRINGTOK. 
Monsieur Herissant, a French anatomist, seems persuaded tliat 
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 
poultry, fjallin<T, and pigeons, co/umha', &c., but immediately 
behind it, on and over the bowels, so as to make a large pro- 
tuberance 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 pincushion 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 Avere 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, cranberries, or 
some such fruit ; so that these birds apparently subsist on 
insects and fruits : nor was there the least appearance of bones, 
feathers, or fur to support the idle notion of their being birds of 
prey. 
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 upon the bowels must, especially when full, be in a 
very uneasy situation during the business of incubation ; yet 
^ Histoire de I'Academie Royale, 1752. 
