natural Hijlory of the Cuckoo. 227 
ones if the young Cuckoo was deprived of the power of dif- 
poffefling them of the neft, I made the following experiment. 
July 9. A young Cuckoo, that had been hatched by a 
Hedge-fparrow about four hours, was confined in the neft in 
fuch a manner that it could not poffibly turn out the young 
Hedge-fparrows which were hatched at the fame time, though 
it was almoft inceflantly making attempts to effedt it. The 
confequence was, the old birds fed the whole alike, and ap- 
peared in every refpedt to pay the fame attention to their own 
young as to the young Cuckoo, until the 13th, when the neft 
was unfortunately plundered. 
The fmallnefs of the Cuckoo’s egg in proportion to the fize of 
the bird is a circumftance that hitherto, I believe, has efcaped the 
notice of the ornithologift. So great is the difproportion, that 
k is in general fmaller than that of the Houfe-fparrow ; 
whereas the difference in the fize of the birds is nearly as five 
to one. I have ufed the term in general , becaufe eggs produced 
at different times by the fame bird vary very much in fize. 
I have found a Cuckoo’s egg fo light that it weighed only 
forty-three grains, and one fo heavy that it weighed fifty-five 
grains. The colour of the Cuckoo’s eggs is extremely varia- 
ble. Some, both in ground and penciling, very much refemble 
the Houfe-fparrow’s ; fome are indiftindUy covered with bran- 
coloured fpots ; and others are marked with lines of black, 
refembling, in fome meafure, the eggs of the Yellow-hammer. 
The circumftance of the young Cuckoo’s being deftined by 
nature to throw out the young Hedge-fparrows, feems to ac- 
count for the parent-cuckoo’s dropping her egg in the nefts of 
birds fo fmall as thofe I have particularifed. If fhe were to do 
this in the neft of a bird which produced a large egg, and 
confequently a large neftling, the young Cuckoo would pro- 
Vol. LXXVII 1 . I i bably 
