250 . Aliempt io systematize — {Oer. 
it may be asked, “ with which of these classes they are most allied?” 
The answer is obvious. All of them consist of tubular vessels of 
various diameter; and all of them transmit and transmute liquids. 
Possessing such strong characteristics of the vital system, they are 
evidently most allied to it. 
In short, digestion prepares the vital matter, which is taken up 
by absorption—the first of the simple vital functions ; respiration 
renovates it in the very middle of its course—between the two por- 
tions of the simple function of cireulation; and generation, de- 
pendant on secretion—the last of these functions, communicates 
this vital matter, or propagates vitality to a new series of beings. In 
such arrangement the digestive organs therefore precede, and the 
generative follow, the simple vital organs; while the respiratory 
occupy a middle place between the veinous and the arterial circula- 
tion. Nothing, however, can be more improper, as the preceding 
observations show, than considering any one of these as a distinct 
elass. - 
The preceding is a natural arrangement of the anatomy of man 
and the higher animals; and its peculiar simplicity is illustrated by 
its involving, in application, that of minerals and vegetables, and 
by its being capable of instant adaptation to physiological science. — 
——— 
In order to arrange animal PuysioLocy, it is only necessary to 
substitute the term “ functions” for .“ organs ;’’ and that science 
will likewise involve, in application, the physiology of mineral and 
vegetable bodies, and be in its turn capable of instant adaptation to 
medical science. 
Thus the functions also are divided into mechanical, vital, and 
intellectual. 
The mechanical functions are subdivided into that of support, 
that ef connexion, and that of locomotion. 
The vital functions are divided into that of absorption, that of cir- 
culation, and that of secretion. 
The intellectual functions are divided into that of sensation, that 
of mental operation, and that of volition. 
A circle of functions, I may observe, thus exist in animals, which 
exist not in minerals or vegetables, because volition, the last of the 
intellectual functions, connects itself to the mechanical ones by ren- 
dering them subservient to it in locomotion. Thus the first and the 
last of these functions are as intimately connected as any of the in- 
termediate ones, and a beautiful circle of organic function and 
organic influence is formed. 
Thus, then, there are three orders both of organs and functions— 
the locomotive, the vital, and the intellectual ; and of each of these 
orders there are also three genera, namely, of the first or locomo- 
tive, those organs and functions which support, connect, and move3 
pf the second, or vital, those which absorb, circulate, and secrete g 
