320 HISTORY OF BOTANY. 



is called artificial, because by a certain rule, plants which have 

 no such resemblance in their properties are brought together. 

 We therefore find in one of the Linna?an classes, the poisonous 

 flag and th* nutritious grass, the grain which supports life, and 

 the darnel which destroys it ; in another the healthful potatoe 

 and the poison mandrake, the deadly hemlock and the grateful 

 coriander. We might thus go through this system and con- 

 stantly meet with similar contrasts in the qualities of the plants 

 which are here collected into the same classes. Nor are their 

 external appearances less unlike ; for here the oleander and 

 pigweed, the tulip and the dock meet in the same classes. This 

 system, it should always be remembered, is not the whole 

 science of botany ; but is the key to the natural method, by 

 which, alone, we should find great difficulty in ascertaining the 

 names of plants ; it is, as it were, a stepping stone by which 

 we must ascend to the valuable knowledge which cannot well 

 be reached in any other way. The more practical a botanist 

 becomes, the less need he has for this assistance ; the eye 

 becomes tyiick to seize on natural characters without reference 

 to the dictionary, as the artificial system is aptly termed. Thus 

 a pupil in studying a language may in time be able in a de- 

 gree to dispense with his dictionary ; but he could never have 

 proceeded thus far without its assistance. For more particular 

 explanations of Jussieu's method, you are referred to the com- 

 parison of that with the method of Linnaeus and Tournefort in 

 the remarks on classification. 



Adanson, previous to the time of the younger Jussieu, had 

 published a system of classification, in which he arranged 

 plants according to the resemblance observed in all their or- 

 gans. In one class, all which had similar roots were placed ; 

 in another, all which had similar stems ; a third was arranged 

 by resemblance of leaves, in their forms and situations ; but the 

 most important distinctions he considered as founded upon the 

 organs of fructification. 



Among other botanists we would notice L. C. Richard, who 

 wrote in French an interesting account of the Orchideae of 

 Europe, and assisted in compiling from ancient works a very 

 useful botanical dictionary. 



Des Fontaines first showed that the stems of monocotyledo- 

 nous and of dicotyledonous plants differ from each other in 

 their structure, and modes of growth ; he divided them into 

 endogenous, growing inwardly, as the palms ; and exogenous, 

 growing outwardly, as the oak. 



France is distinguished for the number and accuracy of its 

 naturalists. Mirbel, a distinguished professor of botany in 



French Naturalists. 



