270 ON THE NATURAL SYSTEM 



Emily. But must you not also arrange, in a similar or- 

 der of gradation, the different points of view under which 

 a plant may be considered ? 



Mrs. B. No doubt ; and, for this purpose, you must 

 be guided by the rules we used in forming the different 

 genera. The most important of which consists in care- 

 fully observing the symmetrical position of the organs in 

 different plants. The natural method of classification con- 

 sists in studying the details of the symmetry of the organs, 

 in the same manner as mineralogy is founded, on the reg- 

 ular symmetrical laws of crytallisation. 



Emily. All this appears to me very ingenious in the- 

 ory, but difficult in practice. Supposing that I were ca- 

 pable of classing the vegetable kingdom according to this 

 order of different organs ; what proof should I have that 

 I was following the right method ? 



Mrs. B. You might afterwards class the vegetable 

 kingdom according to the organs of nutrition, and you 

 could then compare the two arrangements. Now, if, in 

 following two methods, each founded upon a set of differ- 

 ent organs, the same plants are to be met within the same 

 class, is it not infinitely probable that the mode of classi- 

 fication you have adopted is the true one ? the image of 

 what really takes place in Nature ? Thus, the natural 

 order of botany is that in which you obtain the same re- 

 sult, whether the vegetable kingdom be classed according 

 to the organs of re-production, or to those of nutrition. 

 More importance is usually attached to the organs of re- 

 production, as being the most numerous and the most 

 varied ; the classification is, therefore, first made with ref- 

 erence to them, and afterwards with reference to the or- 

 gans of nutrition : the latter of which serves to verify the 

 former. 



Emily. It is like making a proof in arithmetic : but is 

 not this very difficult to reduce to practice ? 



Mrs. B. I do not deny that it is sometimes attended 

 with difficulty. In botany, as in every other science, no 



1455. In what does Mrs. B. tell Emily we must be guided by the rules 

 used in forming the different genera'? 1456. In what consists the nat- 

 ural method of classification! 1457. How else, afterwards, might the 

 vegetable kingdom be classed! 1458. What inference is drawn from 

 the results of two different arrangements'? 1459. What is said of clas- 

 sification as depending on the comparative importance of the organs of 

 re-production and nutrition 7 



