180 The Evolution of Botany. 



devised a system for classification, based upon the floral en- 

 velopes and comprising twenty-three classes. Though his 

 system gave little consideration to the natural relations of 

 plants, a work which he wrote, Institutiones Eei Herbaria, 

 received much recognition before Linnaeus's time. Tourne- 

 fort was the first before Linnaeus to recognize the value of 

 descriptive botany in determining the characteristics of the 

 genera. The specific differences of the genera he treated as 

 of secondary importance. 



In 1789 an attempt was made by Magnol to arrange all 

 known plants into real families. The attempt was a success 

 to some extent. This system comprised seventy-six fami- 

 lies, each family made up of species which resembled each 

 other more than those of another family, especially in the 

 flower and fruit. All the systems theretofore established 

 had been found wanting, the constant discovery of new spe- 

 cies soon proving them to be inadequate. So with Magnol's, 

 though it was of some value when first established. New 

 plants were constantly found which could not be included 

 in any of the seventy-six families without disturbing the 

 arrangement and rendering the system valueless even for 

 the plants it included. 



The fund of known species was about this time again 

 greatly increased by botanical explorations into distant parts 

 of the globe. The tropics especially opened up an immense 

 field to botanical research, with an endless variety of vege- 

 tation, in which botanists soon discerned the entire in- 

 adequacy of all the systems of classification established up 

 to that time. Rheede, Rumph, and Kampfer chose Asia as 

 their field of labor and research, and Sloane and Plumier, 

 Jamaica and America, respectively. Most of the plants 

 Sloane discovered and collected he pressed and preserved, 

 and finally described them in a work which treated of all 

 the plants of Jamaica. These plants constituted a goodly 

 share of his large collection of natural-history specimens 

 which latter he sold to the English Government for a paltry 

 sum, but for which he was better repaid by his success in 

 founding the British Museum with it. Plumier summed 

 up his work in three books, one of a descriptive nature on 

 all the plants he collected in this country, another on the 

 new .plants he found here, and a third upon the American 

 ferns. 



An important epoch in the evolution of botany was the 

 founding of botanical gardens in the larger cities, where not 



