306 VEGETABLE ORGANOGRAPHY. 



they are not united together, and we perceive what they 

 really are when an accidental cause has not prevented 

 them from enlarging. Proceeding thus from the opinion 

 that the primitive nature is symmetrical, that irregularity 

 is produced by different causes which alter this sym- 

 metry, we understand that monstrosities are owing to 

 certain variations of these causes, and that, consequently, 

 they may sometimes enable us to know the causes of 

 derangement when their action has been increased or 

 freed from all complication ; at other times they may 

 show us the symmetrical state when the causes which 

 change it have been weakened or destroyed. 



The whole theory of natural classification evidently 

 rests upon the intimate knowledge of the organs and 

 their modifications. The arrangement of plants in na- 

 tural orders supposes, in my opinion, that we may one 

 day be able to establish the characters of these orders 

 upon what forms the base of their symmetry, and to 

 refer the various forms of the species or genera to the 

 action of causes which tend to alter the primitive sym- 

 metry. Thus, each leaf, like each class of crystals, may 

 be represented by a regular state, sometimes visible, 

 sometimes imaginary ; this is called its Type : unions, 

 abortions, degenerations, or multiplications, separate or 

 combined, modify this primitive type so as to produce 

 the constant characters of the beings they compose. 

 These modifications are constant within certain limits, 

 like the secondary forms of crystals. But each genus, 

 each species, is more or less submitted to the causes 

 which determine them, for plants which have the same 

 type are not more identical than the crystals which have 

 similar primitive molecules. If botany is much behind 

 mineralogy in this respect, it results, on the one hand, 

 from the much greater multiplicity of forms and causes 

 of action ; and, on the other, from all these facts being 



