xil INTRODUCTION. 
(Fringilla celebs) and the Bullfinch (Pyrrhula vulgaris) are showy birds ; 
their mates are more sombre in appearance, and they build open nests, 
where conspicuous or showy plumes would only lead to their destruction. 
The charming Stonechat (Pratincola rubicola), in his garb of chestnut, black, 
and white, is mated to a dull unassuming spouse, who derives her chief 
safety during the trying period of nidification from the dull and sombre 
hues with which she is arrayed. Our second group consists of 
Birds in which the plumage of both sexes is showy or brilliant in 
colour, and which nidificate in open nests.—This group forms one of 
those exceptions which, at first sight, appears seriously to affect the validity 
of the whole theory; but I think it can be shown that the birds included 
in it may possibly secure their safety in other ways. It is unfair to suppose 
that every species is equally liable to the attacks of enemies. Some gaily 
attired female birds may have no special enemies against which to guard— 
their brilliant or showy dress is no disadvantage to them, as is the case 
with many conspicuous insects; and this fact may in itself explain why it 
is that they have assumed such tints. Again, as some female birds became 
more brilliant through natural selection, it is very possible that they 
gradually altered the form of their nests (from an open one to a covered 
one), or if the acquisition of a showy dress did not render them more liable 
to the attacks of any special enemy (and we know that many animals are 
singularly free from persecution), no change in the manner of nesting 
would be required ; and this would explain many of the apparent exceptions 
to the gencral rule that gaily dressed female birds sit in covered nests. 
We must also take into consideration what colours are showy in certain 
haunts. Bright colours that would be very conspicuous in some places 
may be specially protective in others. Take the case of the Tiger’s stripes, 
conspicuous enough in the open or the green forest, but blending beauti- 
fully with the jungle; the light sand-coloured plumage of many desert- 
birds would be conspicuous enough in fertile districts, but on the burning 
sands it is invisible ; many other brightly plumaged birds are safe enough 
in the localities where they build their nests or deposit their eggs; but 
these facts are too often overlooked for want of careful investigation. 
Again, aud most important of all, the colour of the eggs in many cases 
plays a prominent part ; for the moment danger threatens, the ever-watchful 
and conspicuously coloured female quits her charge and seeks her own safety 
in flight, leaving her eggs or young to the safety which their tints insure. 
In this group may be instanced the Orioles, represented in this country by 
the Golden Oriole (Oriolus galbula). All these birds build open nests, the 
sexes are almost alike in colour and of brilliant tints; but they conceal 
their nests amongst the thickest foliage, and, as Mr. Wallace states, 
protect their offspring by incessant anxious watching. 
To this group also belong the Jays, the Crows, the Birds of Prey, the 
