236 CLASSIFICATION OF ANIMALS. 



Origin. 

 Molecular attraction, modified by time and Owe their existence to beings similar to thcm- 

 space, or by the art of man (as in chemistry) ; selves, ])roduced either from eggs, or brought into 

 they are made. existence in a liviug state ; they are hatched or 



bOTTl. 



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 a'ccretion. stances which they absorb, or receive internally ; 



they increase by nourishment. 



Termination. 



They are limited to no particular form (except They have a determinate form and duration ; 

 in the case of crystals) ; tiiey have no life, and are their existence lirminates either by old age, or dis- 

 not subject to death ; they decompose. ease ; they die. 



373. It is difficult to explain the clifFei ince between tlie dif- 

 ferent kinds of organized beings, viz. animals and vegetables ; 

 the lines of distinction often seem to fad*^ 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 inyse and a night- 

 ingale, an oak or ox, but these are animals aad vegetables in 

 a perfect state. 



374:. The perfect animal has the power to move about to seek 

 the nourishment most agreeable ; it can iiiUdY 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 s^sation. It is only when we examine with 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. 



Yegetahles grow, produce seeds which contain the elements 

 of future plants like themselves, and then die. 



A7iimals unite to the properties of vegetables the feeling of 

 their own existence ; or as Linnseus has said, " Stones groio / 

 vegetables grow Siud live j anionals groio^ live^ 2,^^ feel f"^ 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- 

 ies — 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— Animala—- 

 Zoology. 



