OF CLASSIFICATION. 273 



same family, I have before mentioned ; which is, that 

 these alone are susceptible of being grafted on each other. 

 Caroline. These analogies are extremely curious ; and 

 I understand now, perfectly, how much superior your 

 method is to those which merely indicate the name : for 

 when I know that a plant has four stamina, it teaches me 

 nothing further ; whilst the knowledge that a plant be- 

 longs to such or such a family makes me acquainted, in 

 a great measure, at least,^with its structure and its prop- 

 erties. 



Emily. I am glad, Caroline, that you are come round 

 to my opinion ; for I felt a sort of instinctive conviction 

 that it was in analogies of this description that the inter- 

 est of the study of Nature consisted. But pray, Mrs. B., 

 is it not possible to group families together in the same 

 manner as you have done genera ? 



Mrs. B. Yes ; there is still another step in classifica- 

 tion, which brings us to the three great distinctions with 

 which you are already acquainted. 



First. That class of vegetables called Dy cotyledons, 

 relative to their organs of re-production ; and Exogenous, 

 relative to their organs of nutrition. This is by far the 

 most numerous of the three classes, comprehending about 

 two thirds of the vegetable kingdom. 



Secondly. The vegetables called Monocotyledons or 

 Endogenous, according as you allude to their re-produc- 

 tive or nutritive organs. 



Thirdly. The class called dicotyledons, from being des- 

 titute of cotyledons, are also called Cellular, because their 

 nutritive organs have no vascular system. To complete 

 the comparison we have followed up, these three great 

 classes may be considered as the three great continents 

 of the world ; the different families of plants as the vari- 

 ous nations into which these continents are divided; the 

 genera represent the families of each nation ; and the 

 species must be considered as the unity of the scale. 

 This comprehends the whole system of classification, 

 which every day becomes more extended and more per- 

 fect. 



1474. What does Caroline say of the advantages of this mode fof 

 studying Botany! 1475. What makes the first of the three great di- 

 visions of vegetables here pointed out ; and how numerous is this division! 

 1476. What make the second division 1 ? 1477. What make the 

 third divuion'and what is said of those which compose it! 



