214 THE ZOOLOGIST. 
likely that in this case, the Cuckoo had in the course of nature 
laid its egg, and not being able to find an appropriate nest near, 
was driven to make use of that readiest to hand. For nothing 
could be more conspicuous than the contrast between the colours 
of the eggs. Our Victorian Cuckoos are likewise eclectics. The 
Pallid Cuckoo often plants its cream or flesh-coloured and 
spotted eggs in the nests of Honey-eaters, the eggs of which its 
own thus resemble. The Bronze Cuckoo patronises the dome- 
shaped nests of little birds, im which the egg will not be seen, 
and into which it doubtless conveys its eggs by means of the bill, 
for the Cuckoo is much too large a bird to obtain entrance into 
the nest by the tiny opening which serves for the rightful 
owners. The Brush and the Narrow-billed Cuckoos place their 
eggs in the nests of superb Warblers and Acanthizas, and the 
eggs of both are white, with very fine dots. 
The subject it will be seen is as yet still entirely in the 
domain of observation. Experiments are wanting. It is to be 
hoped that they will be forthcoming. Opportunities exist, 
notably in the case of the domestic birds, and of birds which 
breed easily in confinement. But we must not expect too much, 
to be able to produce extreme effects. Mr. E. B. Poulton’s 
interesting series of experiments on the production of colour in 
the pups of certain British Lepidoptera, show that the capacity 
for variation in each species is (for a single generation) limited, 
and that the variations tend in quite definite directions. It is 
probable, however, that results of sufficient, and perhaps in 
some cases of striking, interest are to be obtained by careful 
and systematic experimentation. And the field is open. 

A CUCKOO HATCHING ITS OWN EGGS. 
[In an article in ‘ Die Gartenlaube,’ vol. xxxvi., No. 25, 1888, Herr 
Oberférster Adolf Miiller, who has the reputation of being a good observer, 
has detailed his observations in a case which came under his notice of a female 
Cuckoo incubating and hatching her own egg. The case is so abnormal and 
interesting that we had intended translating the article for publication in 
this Journal; but as the Editor of ‘ The Ibis,’ in the last number of that 
periodical, has saved us the trouble, we may help to make the case more 
widely known amongst ornithologists by quoting his translation, with due 
acknowledgment aud thanks. In return we may save our contemporary some 
