268 THE ZOOLOGIST. 
The natural history of animals may be written in two ways. 
They may be treated as one whole, their various powers and the 
more general facts as to their organisation being successively 
pourtrayed as they exist in the whole series; or one animal may 
be selected as a type and treated of in detail, other types 
successively more divergent in structure from the first being 
described afterwards. In following the latter mode we may 
either begin with one of the most simply organised of living 
creatures, and gradually ascend to the highest and most complex 
in structure; or we may commence with the latter, and thence 
descend to the consideration of the lowest kinds of animated 
beings. Professor Mivart has followed the latter course. 
The bodily structure most interesting to man, his own, was 
the first studied (directly or indirectly), and the names now given 
to different parts of the body in the lower animals have been 
mainly derived from human anatomy. The descending course is 
also that which seems on the whole preferable, for, by com- 
mencing with the class of animals to which man belongs, we may 
proceed from the more or less known to the unknown, and from 
that which is eomparatively familiar to that which is strange and 
novel. 
Having then chosen to begin the study of animals with that 
class to which we belong, it might perhaps be expected that man 
himself might be selected as the type, but, as the author points 
out, a fresh description of human anatomy is not needed, and 
would be comparatively useless to those for whom this work 
is intended, namely, persons who are interested in the zoology of 
beasts, birds, reptiles, and fishes, but who are not concerned in 
studies proper to the medical profession. 
The problem then has been to select as a type for examination 
and comparison an animal easily obtained and of convenient size, 
—one belonging to man’s class, and one not so different from him 
in structure but that comparison between it and him may readily 
suggest themselves to the student. 
In the common Cat we have just such an animal as is required 
for the purpose, and by studying its zoology, as taught by 
Professor Mivart, the student will obtain the knowledge of 
anatomy, physiology, and kindred sciences necessary to enable 
him to study profitably the whole class to which it belongs—the 
class of Mammals. 
