OO 
remarked that the question of difference between 
animals and plants is not a question about what are_ 
the characters peculiar to either, but what are com- 
mon toe both. The elements of the structure of both 
are the same: they both commence in the simple 
- primary cell, and an aggregation of these cells, forms 
the tissues, and makes up the completed organs.— 
We know very well that animals have nerves and 
muscles: that they possess in the higher grades, 
brain, and a heart, and lungs: and that they are 
furnished with a stomach and organs of support : 
that so constitated they move, digest, respire ; that 
they have blood; and that they are endowed with 
more than irritability, a power which is unquestion- 
ably sensation. But what remains of all these cha- 
racters when we descend the long chain formed by 
sensitive beingsand examine them from the first, 
_link to the last? Lungs, glands, brain, skeleton, 
heart, arteries, blood, nerves, and muscles, succes: 
sively disappear, tillat last when we look for the 
mechanism of the internal cavity for the absorption 
of food, which we consider the indispensable cha 
racteristic of an animal, we are not sure whether 
even a stomach is left. | 
We see ordinarily that animals are endued with 
sensation, and with perception. ‘That they possess 
the faculty of transporting themselves from place to 
place; that they live upon organic substances which 
their powers of motion and their ability of perceiv- 
ing, and discriminating, enable them to select ; that 
their food passes through an alimentary cavity from 
which its nutritive properties are transfused by 
