236 
CLASSIFICATION OB ANIMALS. 
Origin. 
Molecular attraction, modified by time and Owe their existence to beings similar to thevf 
space, or by the art of man (as in chemistry) ; selves, produced either from eggs, or brought into 
they are made. existence in a living state ; they are hatched ot 
born. 
Development. 
They grow by the addition of new particles : They develop by assimilating to their nature, 
they are hence said to increase by juxtaposition or converting to their sustenance, foreign sub- 
or accretion. stances which they absorb, or receive internally • 
they increase by nourishment. 
Termination. 
They are limited to no particular form (except They have a <'cterminate form and duration , 
m the case of crystals) ; they have no life, and are their existence I /rminates either by old age, or dis- 
not subject to death ; they decompose. ease ; they die. 
373. It is difficult to explain the difFei 3nce between the dif- 
ferent kinds of organized beings, viz. ani^nals and vegetables ; 
the lines of distinction often seem to fadu so gradually that we 
cannot well decide where the animal ei.ds and the vegetable 
begins. It might at first occasion some surprise that there 
should be the least doubt in distinguishing an animal from a 
vegetable ; one could readily decide between a ^use and a night- 
ingale, an oak or ox, but these are animals a^d vegetables in 
a perfect state, 
374. The perfect animal has the power to move about to seek 
the nourishment most agreeable ; it can utier audible sounds, 
and possesses sensation and apparent consciousness. The plant, 
on the contrary, is confined to a particular spot, having no other 
nourishment than substances which themselves come in contact 
with it ; exhibiting no consciousness, nor, to common observa- 
tion, any sensation. It is only when we examine w^ith close 
attention the various phenomena in the vegetable and animal 
kingdoms, that we learn to doubt as to the exact boundaries by 
which they are separated. 
375. The division of nature into three kingdoms, animal, 
vegetable, and mineral, is very ancient, and appears at first to 
be clear and precise. 
Minerals are destitute of life ; they increase by the accumu- 
lation of new particles. 
Vegetables grow, produce seeds which contain the elements 
of future plants like themselves, and then die. 
Animals unite to the properties of vegetables the feeling of 
their own existence ; or as Linnaeus has said, " Stones grow / 
vegetables grow and live / animals grow^ live,, and feel /" but 
we are not able to decide where, in the vast series of organized 
beings, sensation ceases,^ or where it begins. 
376. A. very general and simple classification of animals is 
Origin of inorganic bodies— Of organic bodies — Development of inorganic bodies — Of organic bod- 
.es — Termination of inorganic bodies— Of organic bodies. — 373. Distinction between the different kinds 
of organized beings.— 374. The perfect animal— The plant.— 375, Minerals— Vegetables— Animals- 
Zoologv, 
