6 DISTINCTION BETWEEN ANIMALS AND VEGETABLES. 



definite length of time, under certain circumstances, their 

 shape and substance. This, however, is owing, not to their 

 continuing to possess life itself, but to the particular nature 

 and composition of the texture of which they are composed. 

 Nothing like this takes place in other substances : they can 

 be destroyed only by the action of some mechanical agent, 

 which separates their parts, or by that of some chemical one, 

 which alters their combinations. 



These are circumstances of distinction common to all liv- 

 ing bodies, whether animal or vegetable. But another sub- 

 ject of inquiry is, How are these to be distinguished from each 

 other? Although it may seem very easy to distinguish an 

 animal from a vegetable, yet the true principle of distinction 

 eludes investigation. Many philosophers have attempted to 

 define wherein it consists, but have failed in the attempt. 

 There is generally little practical difficulty in determining 

 whether any particular substance belongs to the animal or 

 vegetable kingdom, and yet so nearly do the lower species of 

 animals resemble plants in the functions they perform, that 

 it is almost impossible to point out what constitutes the real 

 difference between them. 



Some writers, among whom was the celebrated Buffon, have 

 believed that there is in fact no exact boundary between the 

 animal and vegetable kingdoms; that they run into each other 

 at their extremities, and form so regular a gradation from the 

 one to the other, that no precise dividing line can be drawn 

 between them. But although there is this apparent confu- 

 sion at the boundaries of the two kingdoms, yet, generally 

 speaking, animals are distinguished from plants by their com- 

 position, their structure, their mode of life, &/c. And although, 

 with respect to each particular circumstance, there may be 

 particular exceptions, yet, taking the whole together, we get 

 a good general idea of an animal as distinguished from a 

 plant. Thus the power of locomotion, or of motion from 

 place to place, has been considered as peculiar to animals, 

 and in a general way it is so ; yet there are many exceptions. 

 Oysters, the sea anemone, corals, and corallines, now known 

 to be of an animal nature, " can hardly be said to enjoy the 

 power of locomotion. Many species remain fixed to the 

 rocks on which they were produced, and have no motion but 

 that of extending and contracting their bodies." And, on 

 the other hand, some species of plants are not fixed by roots 

 to one and the same spot, but float about in the sea, receiv 

 ing nourishment from its waters. 



