I 



CHAPTER I. 



ON ANIMAL NATURE IN GENERAL. 



600. An organism, which, in its entire and natural condition^ 

 is regulated by the animal moving forces of its own proper 

 animal machines, is termed a living animal organism^ an animal 

 endowed with life, an animal in the widest sense. In deter- 

 mining the general characteristic distinction of plants and 

 animals, by which we decide whether an organism belongs to 

 the one or the other division, we have to determine whether it 

 is moved in its natural condition, according to the known 

 physical or mechanical laws of gravity, of the force of attrac- 

 tion, of elasticity, of the mechanism of its structure, &c. ; or, 

 according to peculiar laws : — whether a touch, or an external 

 impression upon it, excites it to the movement that we should 

 be led to expect from the known physical and mechanical laws 

 of motion, or whether a movement is excited thereby, which 

 compels us to recognise the phenomena of a peculiar force put 

 into action by this external impression ; and which regulates it 

 according to other and widely different laws. It is not denied 

 that this distinction is always somewhat indefinite, still it 

 exists in nature, and we universally form a judgment thereon ; 

 but we only become more definite, when we have become 

 acquainted with the laws of the animal moving . forces. If 

 some persons distinguish animals from plants by their volun- 

 tary movements, others by their instinctive actions, and others 

 by their external sensations, it all comes to the same thing; 

 inasmuch as we recognise a moving force in animals differing 

 altogether in its nature from physical and mechanical forces, 

 and acting according to altogether different laws. But these 

 distinctions are wholly deduced from the phenomena of the cere- 

 bral forces, while the nerves themselves possess peculiar animal 

 forces, which are not taken into consideration; so that they who 

 adopt this as an universal distinction, are at a loss when they 

 come to decide, whether a certain organism which cannot 



