CLAIMS OF OOLOGY TO BE AN EXACT SCIENCE. 245 
ceryx sonnerati (Banded Bay Cuckoo). Although, according 
to Mr Blanford, the eggs of this bird are supposed to have 
been found in the nest of Otocompsa fuscicaudata, nothing, 
so far as I am aware, is known of the procreant habits of this 
Cuckoo. Yet Mr Davidson took the egg to which I have 
referred from the oviduct of a female which he had shot, so 
that its identity is beyond dispute. When I saw the egg 
I was struck dumb with astonishment, for it so closely re- 
sembles the egg of a Bulbul that by its external appearance 
alone it would be impossible to doubt that it belonged to a 
member of that family. And yet the egg of the Bulbul is 
one of the most highly specialised known to me. These 
specimens clearly demonstrate that parasitism — “ that 
monstrous outrage on nature ”—is, even in birds, of great 
antiquity ; for before such marvellous mimicry was possible, 
structural changes were, in the former case at least, im- 
perative. 
There is, therefore, abundant evidence to show that the 
eggs from which the young of so large a proportion of animals 
are hatched demand at least a share of the scientitic investi- 
gation which has been so liberally bestowed on the parents 
by whom they have been produced. These remarks have 
been compiled far too hurriedly to excite the interest which, 
we are persuaded, the study deserves. To some of you it 
may seem strange that I should have altogether avoided 
the discussion of the obviously much more important claims 
of the subject to be studied in relation to its embryological 
aspect—the microscopic appearance of the protoplasm, the 
chemical composition of the egg, the phases of its develop- 
ment during the process of incubation ; that I should have 
‘confined my attention solely to the treatment of the form 
and colour which these beautiful objects present to the 
intellectual eye of man, as if the shell or case which Nature 
employs to protect a vital germ were of higher value than 
the being which will burst its flimsy envelopment, and 
trample under foot and scatter to the winds its wasted 
fragments. My answer must be, that at present it has been 
my feeble endeavour only to show the analogy which exists 
between the egg and the species with which it is identified ; 
and if by form, or colour, or inherent property, or accidental 
