A THEORY OF BIRDS’ NESTS. 258 
Real or apparent Exceptions to the Law stated at 
page 240. 
The only marked exceptions I have been able to 
discover are the following :— 
1. King crows (Dicrourus). These birds are of a 
glossy black colour with long forked tails. The sexes 
present no difference, and. they build open nests. This 
apparent exception may probably be accounted for by 
the fact that these birds do not need the protection 
of a less conspicuous colour. They are very pugna- 
cious, and often attack and drive away crows, hawks, 
and kites; and as they are semi-gregarious in their 
habits, the females are not likely to be attacked while 
incubating. 
2. Orioles (Oriolidz). The true orioles are very gay 
birds; the sexes are, in many Eastern species, either 
nearly or quite alike, and the nests are open. This 
is one of the most serious exceptions, but it is one 
that to some extent proves the rule; for in this case 
it has been noticed, that the parent birds display 
excessive care and solicitude in concealing the nest 
among thick foliage, and in protecting their offspring 
by incessant and anxious watching. This indicates 
that the want of protection conseyuent on the bright 
colour of the female makes itself felt, and is obviated 
by an increased development of the mental faculties. 
3. Ground thrushes (Pittide). These elegant and 
brilliantly-coloured birds are generally alike in both © 
sexes, and build an open nest. It is curious, however, 
