16 ' SENTIENT PRINCIPLE. 
SENTIENT PRINCIPLE, 
ACCORDING TO THE ORDER OF THE FOUR GRAND 
DIVISIONS OF ANIMALS. 
1 RADIATED ANIMALS. 
The sentient principle in this division of ant- 
mals, is scarcely manifest. Many of them being 
fixed like a plant, and scarcely exhibiting any 
signs of irritability, are hardly distinduiched from 
plants, or even from minerals. if they are sen- 
sible to pleasure or to pain, few of them have the 
means of making their sensations known to man. 
il. MOLLUSCOUS ANIMALS. 
The nervous and circulatory systems being 
more complicated, we infer, from analogy, that 
this division of animais possesses the sentient 
principle in greater perfection. But such is their 
clumsy structure, that they are incapable of evin- 
cing their superiority to the radiated divisions, if 
they are really superior. Some species of snail 
have considerable locomotive power ; and exhibit - 
signs of fear, and retreat suddenly from danger. 
Some species of the bivalves change situation as 
their wants seem to dictate. Little, however, can 
be said of the sagacity of this division of animals. 
WI. ARTICULATED ANIMALS. 
Though the nervous and circulatory systems are 
less perfect in this than in the last division of an- 
imals, their forms being better adapted to the ex- 
hibition of their pleasures, pains, and wants, they 
