the smallest bit of a feather he would not only promptly 
recognize it, but with absolute certainty would assert that it 
belonged to a creature having all the characters above 
enumerated. 
Birds stand isolated and alone. They were recognized as 
forming a closed type. If one studies the embryology of 
birds, the structure of the skeleton and particularly the char¬ 
acter of bird remains buried in the rocks of past geological 
ages, he will realize that the remote ancestors of these creatures 
were scaly reptiles. It adds a curious interest to the study 
when we regard a brilliant plumaged bird flashing in the 
sunlight, or a delicate little brown creature pouring out rap¬ 
turous song, to realize that birds were literally derived from 
cold-blooded reptiles. 
When one considers the horny bill without teeth, as in the 
turtle, the feathers arranged like scales and surviving as 
scales on the legs, the embryos of the two groups identical 
in appearance, he is compelled to recognize the close relations 
of birds and reptiles. 
In the old classification of Cuvier the vertebrates were 
divided into four classes; the fishes, reptiles, birds and mam¬ 
mals. Now the vertebrates are divided into three great 
divisions: the fishes, the sauropsida, which includes the 
reptiles and birds, and the mammals. 
There is no class of animals which has so many points of 
interest as the birds, nor more agreeable features associated 
with the study, wandering as one must over field and forest. 
The wonderful character of migration, their nesting habits, 
questions of protective coloration and mimicry, geographical 
variation, even individual peculiarities, — their songs, etc., — 
all these features may be observed and studied by any in¬ 
telligent mind. 
From an economic point of view the importance of birds 
4 
