THEORIES AND CONCLUSIONS 225 
I will return shortly to discuss further the 
reservations implied in the phrases “ on one of her 
laying-days, ” “ within her territory,' ” and “ suit- 
able accommodation/’ each of which is intended 
to suggest a necessary condition. 
We may unhesitatingly dismiss the idea — 
barely worthy of the name of theory, but not be- 
yond the imaginative power of some naturalists — 
that a hen Cuckoo lays her egg on the ground, 
looks at it to see what it is like, and then careers 
about with it in her bill (or throat) in search of a 
nest, the eggs in which will resemble her own. 
There are variations of this pretty “ guess at 
truth ” : in one version the Cuckoo is credited 
% with the ability to impart to her egg the character- 
istics of the eggs of her prospective dupe. We 
know that she pays a visit to a nest in advance of 
laying in it : obviously (says our theorist), having 
thus gained a mental picture of her dupe’s egg, she 
employs the period of intense concentration, which 
precedes laying, in imparting a similar character 
to her own unlaid egg ! 
It is charitable to suppose that this theory was 
formulated in explanation of the discovery of two 
or three different types of Cuckoo’s egg in the 
nests of one species in a comparatively small area. 
Q 
