ANIMAL. 
may be distinguished from the other orders 
of beings. On this principle, however, oys- 
ters, muscles, cockles, &c. would be almost 
excluded from the class of animals, inas- 
much as they usually adhere, or grow to 
rocks, &c. and yet it is certain that these 
creatures are real animals. But loco-motion 
alone is not sufficient to constitute the 
generic difference of animals ; nor, indeed, 
does it sufficiently distinguish an animal 
from a plant. Many instances are produced 
in which plants manifest loco-motive power. 
This is the case with those denominated 
sensitive plants, many of which, upon the 
slightest touch, shrink back and fold up 
their leaves ; as the snail in the slightest 
touch retires into its shell. There are 
some, on which if a fly perches, instantly 
close and crush the insect to death. Plants 
also change their position and form in differ- 
ent circumstances and seasons ; they take 
advantage of good weather, and guaid them- 
selves against bad weather ; they open then 
leaves and flowers in the day, and close 
them at night ; some close before sun-set, 
and some after ; some open to receive rain, 
and some close to avoid it ; some follow (he 
sun, and some turn from it; the leaves of 
some plants are in constant motion during 
the day, and at night they sink to a kind of 
rest or sleep. It has also been observed, 
that a plant has a power of directing its 
roots for procuring food ; and that it has a 
faculty of recovering its natural position 
after it has been forced from it. A hop- 
plant, for instance, in twisting round a pole, 
directs its course from south to west, as the 
sun does ; if it be tied in the opposite direc- 
tion it dies ; but if it be left loose in this 
direction it will regain its natural course in 
a single night. A honey-suckle proceeds in 
a certain direction, till it be too long to 
sustain itself; it then acquires strength by 
shooting into a spiral form; and if it meet 
with another plant of the same kind, both 
these coalesce for mutual support, one twist- 
ing to the right and tire other to the left. 
There are other instances in which plants 
manifest a faculty of loco-motion ; and, per- 
haps, in almost as eminent a degree as some 
animals. Muscles, e. g. are fixed to one 
place as much as plants, nor- have they any 
power of motion, besides that of opening 
and shutting their shells ; nor do they seem, 
in this respect, to have any superiority, with 
regard to the powers of motion, to the sen- 
sitive plant and others of a similar kind. 
In order, therefore, to form a complete and 
satisfactory distinction between animals and 
vegetables, as well as minerals, it is neces- 
sary to combine with spontaneous loco- 
motion, which they unquestionably possess 
in a more perfect degree than plants, the 
powers of sensation. These seem to be un- 
exceptionably distinguishing and characteris- 
tic. However, M. Buffon, after allowing 
that although progressive motion constitute 
a perceptible difference between an animal 
and a vegetable, this distinction is neither 
general or essential ; proceeds to state, that 
sensation more essentially distinguishes ani- 
mals from vegetables. But he adds, that 
this distinction is neither sufficiently general 
nor decided. If sensation, he says, implied 
no more than motion consequent upon a 
stroke or impulse, the sensitive plant enjoys 
this power ; whereas, if by sensation we 
mean the faculty of perceiving, and of com- 
paring ideas, it is uncertain whether brute 
animals are endowed with this faculty, If 
it should be allowed to dogs, elephants, &c. 
whose actions seem to proceed from motives 
similar to those by which men are actuated, 
it must he denied to many species of animals, 
particularly to those that appear not to pos- 
sess the faculty of progressive motion. If 
the sensation of an oyster, e. g. difier in de- 
gree only from that of a dog, why do we not 
ascribe the same sensation to vegetables, 
though in a degree still inferior ? In examin- 
ing the distinction which arises from the 
manner of feeding, he observes, that animals 
have organs of apprehension, by which they 
lay hold of their food : they search, for pas- 
ture, and have a choice in their aliment. 
But, it is alleged, that plants are under the 
necessity of receiving such nourishment as 
the soil affords them, without exerting any 
choice in the species of their food, or in the 
manner of acquiring it. However, if we 
attend to the organization and action of the 
roots and leaves, we shall soon be convinced 
that these are tire external organs by which 
vegetables are enabled to extract their food ; 
that the roots turn aside from a vein of 
bad earth, or from any obstacle which they 
meet with in search of a better soil; and 
that they split and separate their fibres in 
different directions, and even change their 
form in order to procure nourishment to 
the plant. From this investigation, he con- 
cludes that there is no absolute and essential 
distinction between the animal and veget- 
able kingdoms; hut that nature proceeds 
by imperceptible degrees, from the most 
perfect to the most imperfect animal, and 
from that to the vegetable; and that the 
fresh water polypus may he regarded as the 
