LETTER XXX 

 TO THE SAME 



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. Accord- 

 ing 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 gallince, Colombo?, &c., but immediately behind 

 it, on and over the bowels, so as to make a large protuber- 

 ance in the belly. 1 



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 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, 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 remark- 



1 Histoire de PAcadtmie Roy ale > 1752. 

 VOL. II. I0 5 O 



