OBSERVATIONS ON THE CUCKOO. 63 
accessible to so large a bird as the Cuckoo than that 
of the Hedge-Warbler, which is frequently placed in 
close thorn-hedges or thick bushes. If Cuckoos laid 
in the nests of large birds, their young would not be 
able to dispossess their companions, and would pro- 
bably soon perish for want of proper food. 
It is now well known that Cuckoos, in proportion 
to their size, lay remarkably small eggs, which vary 
considerably both in magnitude and colour. 
. The following Table exhibits the mean weight of 
the Cuckoo and of several birds in whose nests it most 
frequently lays; also the mean weight of their eggs, 
with the ratio of the weight of each bird to that of its 
egg, omitting fractions :— 
. Mean weight |Ratio of birds 
Birds. Mean eight of their sc to their eggs 
ny Brean in grains. in weight. 
Cuckoo 0.0.00... eeeeceeweee 1925 55 35 
TILA REE, vccaianseecwaiiae naan 289 35 8 
Lesser Field-Lark ...... 354 37 9 
Yellow Bunting ......... 412 43 9 
Hedge-Warbler .. ...... 332 385 9 
Pied Wagtail ...........- 333 37 9 
If it be admitted, as I believe it safely may, that 
Cuckoos lay from four to six eggs, it will not be dif- 
ficult to furnish data from which a rough estimate 
may be made of the mean annual destruction occa- 
sioned by young Cuckoos among small birds in 
England and Wales. Early in May, before Cuckoos 
have begun to breed, and before the foliage of forest- 
