208 
NATURAL HISTORY 
LETTER XXX. 
TO THE SAME. 
DEAR SIR, SELBORNE, April 3, 1776. 
lEUR Herissant, a French anatomift, feems perfuaded 
that he has difcovered the reafon why cuckoos do not hatch their 
own eggs; the impediment, he fuppofes, arifes from the internal 
ftrudure of their parts, which incapacitates them for incubation. 
According to this gentleman, the crop, or craw, of a cuckoo does 
not lie before the flernum at the bottom of the neck, as in the 
gall'ina, columha, &c. but immediately behind it, on and over the 
bowels, fo as to make a large protuberance in the belly °. 
Induced by this affertion, we procured a cuckoo; and, cutting 
open the breaft-bone, and expofmg the inteftines to fight, found 
the crop lying as mentioned above. This ftomach was large and 
round, and fluffed hard like a pincufliion with food, which, upon 
nice examination, we found to confift of various infecls ; fuch as 
fmall fcarabs, fpiders, and dragon-flies ; the laft of which we have 
feen cuckoos catching on the wing as they were juft emerging out 
of the aurelia ftate. Among this farrago alfo were to be feen 
maggots, and many feeds, which belonged either to goofeberries, 
currants, cranberries, or fome fuch fruit ; fo that thefe birds ap- 
° Hijloire dc V Academic Royak, 1752. 
patently 
