214 
DARWINISM 
CHAP. 
huge goatsuckers—build very similar nests, and their white 
eggs are protected in the same manner. Some large and 
powerful birds, as the swans, herons, pelicans, cormorants, and 
storks, lay white eggs in open nests; but they keep careful 
watch over them, and are able to drive away intruders. On 
the whole, then, we see that, while white eggs are conspicuous, 
and therefore especially liable to attack by egg-eating animals, 
they are concealed from observation in many and various ways. 
We may, therefore, assume that, in cases where there seems 
to be no such concealment, we are too ignorant of the whole 
of the conditions to form a correct judgment. 
We now come to the large class of coloured or richly 
spotted eggs, and here we have a more difficult task, though 
many of them decidedly exhibit protective tints or markings. 
There are two birds which nest on sandy shores—the lesser 
tern and the ringed plover,—and both lay sand-coloured eggs, 
the former spotted so as to harmonise with coarse shingle, the 
latter minutely speckled like fine sand, which are the kinds 
of ground the two birds choose respectively for their nests. 
“ The common sandpipers’ eggs assimilate so closely with 
the tints around them as to make their discovery a matter 
of no small difficulty, as every oologist can testify who has 
searched for them. The pewits’ eggs, dark in ground 
colour and boldly marked, are in strict harmony with the 
sober tints of moor and fallow, and on this circumstance 
alone their concealment and safety depend. The divers’ 
eggs furnish another example of protective colour; they 
are generally laid close to the water’s edge, amongst drift 
and shingle, where their dark tints and black spots conceal 
them by harmonising closely with surrounding objects. The 
snipes and the great army of sandpipers furnish innumer¬ 
able instances of protectively coloured eggs. In all the 
instances given the sitting-bird invariably leaves the eggs 
uncovered when it quits them, and consequently their safety 
depends solely on the colours which adorn them.” 1 The 
wonderful range of colour and marking in the eggs of the 
guillemot may be imputed to the inaccessible rocks on which 
1 C. Dixon, in Seebohm’s History of British Birds, vol. ii. Introduction, p. 
xxvi. Many of the other examples here cited are taken from the same valu¬ 
able work, 
