18 INTRODUCTION. 



cate observation can penetrate no farther than the mystery of the 

 pre-existence of the germs. 



Divisions of organized beings into Animals and Vegetables. 



Living or organized beings have always been subdivided into ani- 

 mate beings 9 that is, such as are possessed of sense and motion, and 

 into inanimate beings, which are deprived of both these faculties, 

 and are reduced to the simple faculty of vegetating. Although the 

 leaves of several planks shrink from the touch, and the roots are 

 steadily directed towards moisture, the leaves to light and air, and 

 though parts of vegetables appear to oscillate without any apparent 

 external cause, still these various motions have too little similarity 

 to those of animals, to enable us to find in them any proofs of per- 

 ception or will. 



The spontaneity in the motions of animals required essential mo- 

 difications even in their purely vegetative organs. Their roots not 

 penetrating the earth, it was necessary they should be able to place 

 within themselves a supply of aliment, and to carry its reservoir 

 along with them. Hence is derived the first character of animals, 

 or their alimentary canal, from which their nutritive fluid penetrates 

 all other parts through pores or vessels, which are a kind of internal 

 roots. 



The organization of this cavity and its appurtenances required 

 varying, according to the nature of the aliment, and the operation it 

 had to undergo, before it could furnish juices fit for absorption; 

 whilst the air and earth present to vegetables nought but elaborated 

 juices ready for absorption. 



The animal, whose functions are more numerous and varied than 

 those of the plant, consequently necessitated an organization much 

 more complete; besides this, its parts not being capable .of preserv- 

 ing one fixed relative position, there were no means by which exter- 

 nal causes could produce the motion of their fluids, which required 

 an exemption from atmospheric influence; from this originates the 

 second character of animals, their circulating system, one less essen- 

 tial than that of digestion, since in the more simple animals it is 

 unnecessary. The animal functions required organic systems, not 

 needed by vegetables that of the muscles for voluntary motion, and 

 serves for sensibility; and these two systems, like the rest, acting 

 only through the motions and transformations of the fluids, it was 



