PART III. 



CliASSlFICATIOKT 



LECTURE XXI 



Method of tournefort — system of LiNNiEos— natural methods — mets* 



CD of JUSSIEU — COMPARISON BETWEEN THE CLASSIFICATIONS OF TOURNB> 

 FORT, LINN5:US, AND JUSSIEU. 



Let us now imagine tlie whole vegetable kingdom, comprising in-' 

 numerable millions of individual plants, to be spread out before a 

 botanist. Could he, in the course of the longest life, number each 

 blade of grass, each little moss, each shrub, or even each tree? If 

 he could not even count them, much less could he give to each one a 

 separate name and description. But he does not need to name them 

 separately, because that nature has arranged them into sorts or 

 kinds. 



Were you sent into the fields to gather flowers of a similar kind, 

 you would need no book to direct you to put into one parcel, all the 

 red clover blossoms, and into another, the white clover ; while the 

 dandelions would form another group. These all constitute differ- 

 ent species. Nature would also teach you that the red and white clo- 

 ver, although differing from each other in some particulars, yet bear 

 a strong resemblance. By placing them together you form a genus, 

 and to this gejius you refer all the different kinds or species of clover. 

 When you see the common red, damask, and cinnamon roses, you 

 perceive they all have such strong marks of resemblance as to en- 

 title them to be placed together in one genus. But yet you know 

 that the seed of a damask rose would never produce a red rose- 

 One species of plants can never produce another species. 



The whole number of species of plants, which have been named 

 and described, including many which have been I'ecently discover- 

 ed in New Holland, and about the Cape of Good Hope, is said to 

 be 56,000.* 



If species of plants were described without any regular order, we 

 could derive neither pleasure nor advantage from the study of prac- 

 tical botany. When we wished to find the name of a plant, we 

 should be obliged to turn over the leaves of our books without any 

 rule to guide us in the search. 



The necessity of some kind of system was so apparent, that many 

 attempts for the methodical arrangement of plants were made be- 

 fore the time of Linnaeus; but his system was so superior to all oth^ 

 ers, that it was no sooner published to the world, than it was adopt-^ 

 ed by the universal consent of all men of science. 



Previous to this time, Tournefort, a native of France, had pub- 

 hshed an ingenious method of arrangement, beautiful by its sinipli^ 

 city, but imperfect, on account of the vagueness of its application. 

 The characters of his classes were founded upon the absence, pres- 

 ence, and /or?n of the corolla. Tournefort made twenty-two classes j 

 these he subdivided into sections or orders. 



* As recently reported by the Baron Humboldtj to the French National Institute. 



Nature arranges plants into kinds or sorts— Examples— Number of species of 

 plants— Necessity of order in description— Attempts at arrangement tnade before the 

 time of Linnteus-^Tournefort's classesj on what founded? 



