546 THE ZOOLOGIST. 



immediately from the egg like Partridges, &c, and are withdrawn 

 to some flinty field by the dam, where they skulk among the 

 stones, which are their best security, for their feathers are so 

 exactly of the colour of our grey-spotted flints, that the most 

 exact observer, unless he catches the eye of the young bird, may 

 be eluded." * The same observer records an illustration of active 

 mimicry in a Willow- Wren : — " This bird a friend and myself had 

 observed as she sat in her nest, but were particularly careful not 

 to disturb her, though we saw she eyed us with some degree of 

 jealousy. Some days after, as we passed that way, we were 

 desirous of remarking how this brood went on ; but no nest 

 could be found, till I happened to take up a large bundle of long 

 green moss, as it were carelessly thrown over the nest, in order 

 to dodge the eye of any impertinent intruder." f 



Active mimicry, rather than natural selection per se, appears 

 very largely to account for the assimilative colouration of birds' 

 eggs to their nests or environment. Without recapitulating 

 all the evidence which can be readily obtained from so many 

 sources — either by observation, or reference to much illustrated 

 literature — we may safely conclude, with Mr. Wallace, that on 

 the whole, " while white eggs are conspicuous, and therefore 

 especially liable to attack by egg- eating animals, they are con- 

 cealed from observation in many and various ways." J This is a 

 very important consideration before we proceed farther. We find 

 a great number of white or prominent eggs, apparently unaffected 

 by " natural selection," but preserved by intelligent concealment, 

 which is only a form or phase of what we have noted before, and 

 to what will be referred to again on this very matter of birds' 

 eggs, as active mimicry. If the process of natural selection was 

 to be applied, according to a very frequent method, as universal, 

 then birds arising from these white and prominent eggs would 

 seem in course of time to be doomed to destruction. But we find 

 nothing of the kind. Natural selection is here replaced by the 

 evolution of intelligence or active mimicry. True, it may be 



:;: ' Nat. Hist. Selborne,' Harting's edit. p. 55. — 'Grant Allen, in the 

 introduction to his own edition of White, refers to this observation as " the 

 germ of the theory of Protective Mimicry." 



f Ibid. p. 175. 



