SYSTEMS OF BOTANICAL CLASSIFICATION. 



173 



Linn«us had moreover tlie merit of refonniug, 

 or rather of creating, the nomenclature and sy- 

 nonymy of botany, which his predecessors had 

 left in so imperfect a state. Tournefort himself 

 had traced the path to he pursued, without, how- 

 ever, clearing away all the obstacles. Hitherto 

 each species was still named by a characteristic 

 phrase, in which the distinctive characters were 

 frequently not included. These phrases were so 

 long that it was very difficult to retain any num- 

 ber of them in the mind. Linnieus gave a pro- 

 per or generic name to each group or genus, in 

 so far following the example of Tournefort. He 

 further designated each species of these genera 

 by a specific name added to the generic ; and, by 

 this ingenious contrivance, greatly simplified the 

 already very extensive study of botany. 



The sexual system of Linnseus, which was 

 rendered so seductive by its extreme simplicity, 

 produced a sudden revolution in the science, and 

 was every where received with an enthusiasm 

 which it would be difficult to describe. 



When the first emotions of admiration which 

 a great discovery always inspires, had somewhat 

 subsided, it was soon perceived that this system, 

 ingenious as it was, yet possessed some disad- 

 vantages, and was not entirely unobjectionable. 

 Being founded upon the absolute consideration 

 of a single organ, it often separated plants which 

 all their other characters seemed to unite beyond 

 tlie possibility of their ever being disjoined ; for 

 it had already been perceived tliat certain genera 

 of plants possess so many points of contact and 

 of mutual resemblance, and are so united by their 

 general characters, that they seem, as it were, 

 members of the same family. Thus the grami- 

 nece, labiaim, umbelliferce, leguminosce, cruciferce, 

 and several other groups equally natural, had al- 

 ready been brought together in the form of distinct 

 tribes. The separation of plants which it miglit 

 be considered so necessary to keep together, was 

 therefore a great defect in the artificial system of 

 Linnseus. Thus the gramineae were dispersed in 

 the first, second, third, sixth, twenty-first, and 

 twenty-third classes of his system. The labiatse 

 were placed partly in the second class and paitly 

 in the fourteenth. Most of the natural tribes, 

 which had already been admitted as such by a 

 great number of botanists, were separated in the 

 same manner, as Linnaius found himself obliged 

 to adhere strictly to the principles of his system. 

 Anotlier method, which, retaining the already 

 acknowledged affinities of plants, might present 

 their general distinctive characters, was, there- 

 fore, preferable to a system which, however in- 

 genious, was faulty in one of the most important 

 jioints. 



Adanson gave the first sketch of such a me- 

 thod. Bernard de Jussieu searched, during forty 

 yeam, for the most solid and constant characters 

 on which to found it. He studied with the 



greatest care the natural affinity of the species 

 and genera. But his nephew, Antoine Laurent 

 de Jussieu, bringing together the rich materials 

 collected by his uncles, and adding to them the 

 numerous observations which he had made him- 

 self^ was the real author of the method of na- 

 tural families. It was in his Genera Plantarum, 

 a work stamped with the impress of genius, and 

 one of the finest monuments of the progress of 

 botany, that he laid the foundations of a method, 

 which must one day be the only one adopted and 

 followed by all unprejudiced minds, it being un- 

 questionably superior to any that has hitherto 

 been published. 



It has not as its basis the consideration of a 

 single organ, but examines all the charactera 

 furnished by every part of a plant, and brings 

 together all those which bear the greatest affin- 

 ity and resemblance to each other. It is owing 

 to this method that botany, within the last forty 

 years, has made such rapid progress, and has as- 

 sumed the first rank among the natural sciences. 



It may be here observed, that there are two 

 very distinct kinds of classification in natural 

 history. In one, the consideration of a single 

 organ is taken as the basis. Thus Tournefort 

 employed the corolla, and Linnseus the stamina, 

 for establishing their principal divisions. The 

 name of systems has been given to these purely 

 artificial arrangements. It will easily be con- 

 ceived that a system, having no other object than 

 that of enabling one to find out the name of a 

 plant with facility, affbrds no idea of its organ- 

 ization. Thus, when we have found that a plant 

 belongs to the first class of the system of Lin - 

 nseus, or of that of Tournefort, all that we know 

 is, that, in the foi-mer case, it has a single stamen, 

 and that in the latter its corolla is monopctalous, 

 regular, and bell-shaped ; but these systems dis- 

 close to us nothing respecting the other parts 

 which compose the plant, of which they have 

 taught us only the name. In the second kind 

 of classification, which has received the name of 

 method, properly so called, as the basis of each 

 class rests upon the total sum of all the charac- 

 ters derived from the diff'erent parts of the plant, 

 when we come to one of these classes, we already 

 know the more prominent points of the organ- 

 ization of the plant whoso name we are desirous 

 of knowing. Should we, for example, have 

 found, by means of analysis, that the plant which 

 we are examining belongs to the fourth class of 

 Jussieu, this circumstance apprises us that it is 

 a phanerogamous plant, that its embryo has only 

 a single cotyledon, that it has only one flora) 

 envelope, and that its stamina are inserted upon 

 the ovary. 



We shall now proceed to explain the three 

 most prominent and important systems of classi- 

 fication, that of Tournefort, Linna;us, and Jus- 

 sieu. 



