OF VEGETABLE SYMMETRY. 307 



submitted to a peculiar force (the vital force), the laws of 

 which are much more obscure and difficult to study than 

 those of affinity and attraction. 



The simple description of vegetable facts and forms 

 has been singularly improved since the knowledge of 

 some general laws has caused describers to reflect upon 

 what they see. Those who refuse to believe these laws, 

 may, without doubt, describe the aberrations as the 

 natural state, because nothing causes them to doubt that 

 what they see is contrary to order ; they may easily 

 neglect minute organs, because nothing indicates their 

 existence, and they may take much trouble in describing 

 in detail certain peculiarities, which a few words, 

 founded upon analogy, would have expressed with more 

 clearness. Lastly, when two persons have described 

 the same object in a contradictory manner, which unfor- 

 tunately is not seldom the case, we have evidently no 

 other means of discerning the truth than by the greater 

 or less analogy of the descriptions with the laws of sym- 

 metry. For, in order to place plants in a rational order, 

 we most constantly decide it upon more or less incor- 

 rect descriptions, for the period no longer exists when 

 one man can see for himself all known plants. 



Thus, in proportion as science makes new progress, 

 we more and more perceive the necessity of knowing 

 the general laws of organic symmetry. This necessity, 

 perceived by all those who love general truths, has 

 caused two divisions or schools to arise. 



Some have endeavoured to establish laws upon the 

 structure of beings from general considerations, and, as 

 it is usually said, a priori. Others have attentively 

 observed the facts which would seem to remove laws 

 from regularity ; they have seen that by separating 

 almost all after uniform principles, and thus grouping 

 the apparent irregularities, they referred them again to 



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