238 Animal Life 
The Swift, buildmg in holes of old masonry, lays a chalk-white egg; the 
House-Martin, building a nest encased with mud and having one small hole for 
entrance and exit, lays a white egg; while its cousin the Swallow, building a less 
protected nest, lays eggs more or less spotted with blackish-purple and shades of red, 
which harmonise well with the feathers composing the lining of the nest. 
The eggs of the House-Sparrow so exactly resemble the lining-feathers of the 
nest that, should an unbidden guest visit it and tear a portion of the structure 
away, the eggs would not easily be discovered. 
It may occur to the reader that it is strange the eggs of pigeons should be white, 
although some of these birds build in exposed trees. The explanation of this is as 
follows: Possibly the original pigeons all built in holes im trees and rocks, as a 
number of species do now. Thus the species that build in trees have 
originated from such ancestors ; and, as the first arboreal members 
of the tribe usually produced their eges rather late im the season 
(as they do now), there was no need for them to be protectively 
coloured, since the fully-developed leaves of the trees above formed 
a more effectual means of con- cealment. And, by constructing 
the nest in such a way as to allow a free passage of light from 
above at various points, it is next to impossible to detect the 
presence of white eggs from beneath, and this is probably the 
reason why the eggs of these birds have remained as white as 
those of the first pigeons, which pro- 
duced white eggs in accordance with their 
habit of frequenting dark holes where colours 
would serve no practical purpose. 
Most of the Crow tribe lay their eggs in 
the spring or early summer—hence the 
predominant shades of ereen, which match 
well with their young- leafy surroundings and 
thus escape discovery Ne a from above, the point 
from which danger principally threatens. 
The Jackdaw usually builds in holes of trees, walls or rocks, 
and as there is now little need to preserve those green tints which 
were in all probability at one time essentially useful to the welfare 
of its eggs, they have lost most of their green shades and are 
rather sparsely spotted, or rather speckled, with black and grey, 
while the ground-colour, though usually a pale bluish-green, 1s 
often quite white, or only very shehtly tinted. 
The Starling, which has probably built in holes for a con- 
siderable time, lays a nearly white or pale greenish-blue egg. 
The eggs of the Jay, which TURTLE-DOVE. are deposited in a nest of sticks 
among the branches of woodland COIN CHAVEBc trees, are almost identical with 
. ; QUAIL. Marae 
their surroundings. ; Some individuals of the Black- 
bird build in hollows in the banks of ditches, etc. a habit which~ they probably 
retain through life, and in this case the eggs are so similar to the earth and 
rootlets among which the nest is placed that I once searched for a considerable time 
where I knew a nest to exist, and had to abandon the idea of finding it until the 
bird began to sit. In this instance the old bird always left the nest before danger 
was at close quarters, as the eggs were practically invisible when left to take care of 
themselves. The eggs of such blackbirds are occasionally so similar to those of the Jay 
that they are sometimes sold as such, 
