BAROX CUVIER. 37 



tissue, and this combination, are in some measure the re- 

 sults of the action of the vital principles which gave them 

 being, and continue to preserve them, it is evident that these 

 principles can only have in them their source and their 

 foundation. Thus, if the first assemblage of these me- 

 chanical and chemical elements of a living body has been 

 effected by the vital principle of the body from which it de- 

 scends, we cannot but find in it a similar force, and the 

 causes of this force, in order to exercise a similar action in 

 favour of the body, which, in its turn descends from it. 

 But, although our knowledge of the composition of living 

 bodies is too imperfect to deduce clearly from it the effects 

 they present to us, we may, at any rate, make use of that 

 which we do know, in order to recognize these bodies, even 

 when inactive, and to distinguish their remains after death ; 

 for in no unorganized bodies do we find fibrous or cellular 

 tissue, or that multiplicity of volatile elements which forms 

 the characters of organization, whether actually living, or 

 having lived. Thus Vvhile inanimate solids are only com- 

 posed of polyhedral particles, mutually attracted by the faces 

 they present : while they only resolve themselves into a 

 limited number of elementary substances ; while they are 

 only formed by a combination of these substances, and an 

 aggregation of these particles ; while they only increase by 

 the juxta-position of new particles, which envelope the first 

 mass by their la3^ers ; and while they are only destroyed by 

 some mechanical or chemical agency, which alters their 

 combinations ; on the other hand, organized bodies, com- 

 posed of a tissue of fibres and plates, the intervals of which 

 are filled with fluids, resolve themselves almost entirely into 

 volatile substances, spring from bodies similar to themselves, 

 from which they are only separated when they can act by 

 their own strength, assimilate themselves incessantly with 

 foreign substances, and, introducing these substances be- 

 tween their particles, increase by internal force, and at 

 length perish by this internal force, by the effects even of 

 their vital principle. To originate in generation, to increase 

 by nutrition, and to end by death, are the general and com- 

 mon characters of all organized bodies ; 'out if several of 

 these bodies only exercise these and their necessary func- 

 tions, and have only the organs requisite for this compara- 



D 



