FROM THE CRADLE TO THE GRAVE. 
81 
very few in number, whose sex may be determined, even 
in the nest-dress, inasmuch as the young male resembles 
the father, and the young female the mother. Long 
study of the feathered creation is necessary to enable one 
to determine correctly the age of each individual bird, 
and even then the very best naturalists are at times 
subject to be misled and deceived by young birds, 
describing them as new species: this often occurs when 
comparing the young of Raptores and aquatic birds with 
adult specimens, especially among the Terns, Gulls, Gan- 
nets and Cormorants. With the latter, as also Vultures, 
Eagles and many Falcons, the form and proportions, and 
not the colours, form the basis upon which the un¬ 
initiated should seek to distinguish the species; shape 
and construction are, however, more or less the common 
property of allied forms, and for this reason cannot 
always be relied on for the decided determination of a 
distinct species. The individual feathers of young birds, 
Vultures especially, are sometimes differently constructed 
to those of the mature specimen; the decorative insignia 
are wanting—for instance, tufts of feathers of a quite 
peculiar construction which grace the old birds, and 
thus it often happens that scarce a single characteristic 
is to be found common to both. It is only when a bird 
has donned his courting suit that he is not easily to be 
mistaken. 
All the changes of plumage to which the bird is 
subject are brought about by one of the most important 
recurrent events of the life of a bird, in conjunction with 
the casting of the feathers and changes of colouring: 
this action is termed “ moulting,” and differs very much 
in the effect which it has upon the entire plumage, and 
also as to the time within which such changes occur. 
M 
