INTRODUCTION. 3 
their existence. Birds have also definite relations to past time 
—relations which are revealed to us by their fossil remains 
preserved in different strata of the earth’s crust. 
The more numerous any set of objects may be, the more 
necessary it is to arrange them in groups—z. ¢., to classify 
them. Without this it is impossible for us to study and com- 
prehend such objects. As Birds are very numerous in their 
kinds, their classification is especially necessary, while the 
very uniformity of their structure makes that process especially 
difficult. Nevertheless, the study of their classification is a very 
interesting one, on account of their structure, their powers, 
the geographical relations of different kinds of Birds and their 
relations with the past history of our planet. 
Thus the science of Ornithology deals with the structure, 
functions, external relations, and classification of Birds. But 
in order that the student may be able to study these subjects 
profitably, he should possess some preliminary acquaintance 
with a considerable number of different kinds of Birds. He 
will again and again meet with the names of different kinds, and 
of groups of kinds, of Birds; and no advance in Ornithological 
knowledge can be made by a reader who, when he meets with 
any such name, is not provided with a corresponding mental 
image sufficiently distinct to enable him to group his freshly 
acquired knowledge around it. 
Our first task, therefore, shall be to place before the student 
the names and figures of such a number of Birds of different 
kinds as may enable him to acquire a certain preliminary grasp 
of his subject—the subject-matter of his subsequent study. It 
will be well, however, that the reader, after having perused 
this introduction, should repair to some Zoological Garden or 
Museum, and there acquaint himself more fully with the external 
aspect of the Birds here referred to. Failing this, the next best 
thing he can do is to carefully examine all the good pictures of 
Birds he can get access to. 
It is always well to advance from the better known to the 
less known or unknown. We will therefore begin with that 
Bird which must be most familiar to al our readers—the 
Common Fowl. 
All the various breeds of this animal have been derived from 
one or more wild species—Jungle-fowls—which have their 
home in India and the Indian Archipelago, but were introduced 
into Europe in very ancient times. 
B2 
