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W, H. DALRYMPLE. 
second, ruminantia, embracing the ox, sheep, goat, camel, etc., 
and non-ruminantia, represented by the porcine tribe. To the 
(2) order of the mammalia—the carnivora—belong the cat, dog, 
etc. 
Going back to the subject of anatomy, or zootomy, which 
means the anatomy of animals, let us for a moment glance at 
the subsections with which the student of comparative medicine 
has to be familiar. His first object may be to investigate, ex¬ 
clusively, the structure of a particular species ; this is special 
anatomy. He may desire to bring under observation the struc¬ 
ture of different species of animals, in order to trace their points 
of resemblance, and would then be laboring in the field of com¬ 
parative anatomy. If concerned with the elementary cells and 
tissues of which the various organs of the body are built up, his 
work would be in histological anatomy. And further, if tracing 
up the succession of forms exhibited by the individual from the 
date of conception to the period of adult life, he would be mak¬ 
ing a study of developmental or etnbryological anatomy. And 
still further, were the student endeavoring to group together 
facts relating to structure, in order to discern the natural laws 
that determine the form of different parts of the body, he would 
be viewing the subject from a morphological standpoint. These 
three latter are subdivisions of special anatomy, but there are 
two distinct ways in which the special anatomy of an animal 
may be prosecuted. I11 the first of these, the different groups or 
systems of similar organs are studied separately, and in order in 
which one would naturally proceed had we the power to build 
up an animal. This is termed systematic or descriptive an¬ 
atomy. By the second method the student would investigate 
the different structures in the order of their position in the same 
part of the body, such as he would find them presented in the 
course of a dissection. This constitutes topographical anatomy. 
In the first case, he would be proceeding by synthesis ; in the 
second, by analysis, for the purpose of familiarizing himself with 
the structure of the animal body. So much, then, for a brief 
allusion to structure. 
