PERCHING BIRDS. 153 
he communicated his views in the article in question. 
Dr. Baldamus says he discovered that the cuckoo de- 
posits her eggs in the nests of thirty-seven different 
species, and that in by far the greater number of in- 
stances these eggs bore the same colour and markings 
as the eggs of the birds in whose nests they were laid. 
He enters into details, and proves this to his entire 
satisfaction, giving a list of all the species in whose nests 
he and his friends found cuckoo’s eggs, summing up the 
question thus:—“ Therefore I do not hesitate to set 
forth as a law of nature, that the eggs of the cuckoo are, 
im a very considerable degree, coloured and marked 
like the eggs of those birds in whose nests they are 
about to be laid, in order that they might the less easily 
be recognised by the foster parents as substituted 
ones.” 
' He then asks the question, “ Does the same hen 
cuckoo lay eggs of the same colour and markings 
only ? and so, 1s she limited to the nests of but one 
species? Or else, does the same individual lay eggs 
of different colour and markings, according to the 
character of the eggs amongst which her own will be 
intruded ?” 
In discussing these points the Doctor considers it by no 
means “improbable” “that the sight of the eggs lying 
in the nest has such an influence on the hen which is 
just about to lay, that the egg which is ready to be laid 
assumes the colour and markings of those before her,” 
and adduces as evidence in proof the account of the 
proceeding of the patriarch Jacob as given in Genesis 
xxx. 37, &e. 
His final conclusion, however, is this, “that every hen 
cuckoo lays only eggs of one colouring, and con- 
