INTRODUCTION. 
T is not necessary in a book of this character to 
enter into minute details as to the anatomy and 
physiology of birds, important as these are to a 
thorough comprehension of bird-life as a whole. We 
will pass over, too, the subject of the relationship 
borne by this class of animals to the other great 
groups of the animate world. 
It is sufficient to say that birds are known instantly 
by their feathers, a covering not to be confounded 
with any other, and peculiar to them. Birds, as we 
know, are creatures of flight, but so are insects and 
some of our mammals, and indeed, in whatever way 
we propose to distinguish this group from the others, 
it will be found that there are some exceptions to be 
made, but not one in the matter of the first distinctive 
feature that I have mentioned, that of feathers, which 
are beautiful in themselves because of their delicate 
structure, and often so exquisitely colored that they 
rival the richest orchids of the tropical jungle. 
Feathers in some respects are so far like the hair 
of mammals that a close relationship in their nature 
has been confidently asserted ; but it is now generally 
agreed that the true relationship is with the scales of 
reptiles, and this is the more probable, in that the 
general relationship between reptiles and birds is very 
9 
