IO ANATOMY OF THE RABBIT. 
to be considered. Thus, dissection is to be recognized as a method 
of displaying structure of a gross and special kind. It consists in 
the orderly exposure and displacement of organs with the object 
of observing their features and relations’ to surrounding parts. 
~The plan is essentially one of analysis, since conceptions of structure 
are based on the recognition of differences, the latter being estimated 
by various features, such as form, color, texture, or position. On 
the other hand, because of the class of structure with which it deals, 
dissection is also to be recognized as a preliminary method in 
comparison with various others involving the use of the microscope. 
THE INTERPRETATION OF STRUCTURE. 
Gross structure is, in a sense, only the outward expression of the 
finer microscopic structure underlying it, the latter being the true 
basis of the body. This refers not so much to the individual 
features of the organs as to the relation existing between their 
appearance as gross objects and their tissue composition. Since 
this relation is more fully discussed below under the head of general 
anatomy, it need only be mentioned here as an element in the 
interpretation of structure as viewed from the gross standpoint. 
All animal structure, however, may be considered from two points 
of view—physiological and morphological. 
The physiological aspect of structure concerns the functions 
or activities of the living organism and of its individual parts. The 
contraction of a skeletal muscle is a change in the axial relations of 
living protoplasm, but the form and connections of the muscle are 
such that the contraction results in movement of one bone upon 
another. The excretion of urine on the part of the kidneys is the 
final stage of a process which rids the body of soluble waste nitro- 
genous materials by discharging them into a system of tubes 
connected with the outside of the body. What is important in 
these, as in a multitude of analogous cases, is that structure and 
function are intimately related, and in point of interpretation, 
serve to explain one another. 
The morphological aspect of structure concerns various 
features of form and arrangement which, although they have been 
developed on a basis of utility, cannot be explained directly on that 
