PREFACE. 
The study of British Zoology is peculiarly attractive to the 
intelligent observer of nature in this country, by the facility 
with which many species, in the different groups of animals, can 
be procured for accurate examination. Their forms, structure, 
and successive developement, can be traced in detail, together 
with the functions which they exercise, and the various circum- 
stances by which they are controlled. In this manner just con- 
ceptions of the laws of organization, and the limits to the distri- 
bution of the species, may be acquired, and the, mind qualified 
for speculating on the more extended relations of the animal 
kingdom. A valuable collection of facts will likewise be secured, 
by which the most fascinating generalisations may be tested — 
those productions which, like a map, should always be received 
with suspicion, if inaccurate within the sphere of individual ob- 
servation. 
These views have long exercised an influence in this country, 
and given rise to those various attempts to enumerate and de- 
scribe British animals, which, for more than a century, have 
been presented in succession to the public. During this ex- 
tended interval, the science of zoology has experienced several 
remarkable changes, each producing a corresponding effect on 
the British Fauna. If anatomy and physiology be regarded as 
the basis of zoological science, the history of species will include 
a description of their structure and functions, along with their 
external characters. If anatomy and physiology be discarded as 
foreign to the subject, and the professed naturalist acknowledge, 
without a blush, his ignorance or his contempt of both, then 
the history of species will be chiefly occupied with the details 
of external appearance. Such diflPerent conditions have pre- 
