166 LANIADA. 
not believed formerly, it is now very well known that 
many birds build nests and produce young before they 
have attained their own adult plumage. 
Baron Cuvier has stated, that when the adult female 
bird differs from the male in the colour of her plumage, the 
young birds of both sexes, in their first feathers, resemble 
the female; the young males afterwards putting forth the 
colours that indicate their sex. When the adult male and 
female are of the same colour, the young then have for a 
time a plumage peculiar to themselves. The Pheasant 
may be quoted in illustration of the first law, and the 
Partridge as an example of the second. ‘To these two, a 
third law may be added: whenever adult birds assume a 
plumage during the breeding season decidedly different in 
colour from that which they bear in the winter, the young 
birds of the year have a plumage intermediate in the ge- 
neral tone of its colour compared with two periodical 
states of the parent birds, and bearing also indications of 
the colours to be afterwards attained at either period. 
There are various modes by which changes in the ap- 
pearance of the plumage of birds are produced. 
By the feather itself becoming altered in colour. 
By the bird’s obtaining a certain addition of new fea- 
thers without shedding any of the old ones. 
By an entire or partial moulting, at which old feathers 
are thrown off and new ones produced in their places. 
And by the wearing off the lengthened lighter coloured 
tips of the barbs of the feathers on the body, by which the 
brighter tints of the plumage underneath are exposed. 
These changes will be noticed under the different species 
most affected by them. 
