T1IK BOTANISTS OF I'll 1 1. A !>KI. I'll I A. 



I'ursh published in London, in Lsl4, his valuable and com- 

 prehensive work, Flora America' Septentrionalis.* 



Arranged according to the Linnsean system tin-re ap- 

 peared in 1. SIX, in two volumes, Dr. William P. ( '. Barton's-:- 

 Compendium Flora' Philadelphia', a hastily digested, but 

 thoroughly useful hand-hook of the region. 



Botanical works and papers began now to multiply, 

 and the third period of Philadelphia botany was fairly 

 entered upon with the publication in 1818 of Xuttall's 

 "Genera of North American Plants/' at Philadelphia.! 



(3) Development of the Natural System under the in- 

 fluence of the doctrine of the constancy of species. A 

 new direction to the study of systematic botany, and mor- 

 phology was given in France, where the sexual system had 

 never met with great acceptance. Bernard de Jussien and 

 bis nephew, Antoine Laurent de Jussieu, taking up Lin- 

 na-us' profounder and properly scientific efforts, made tin- 

 working out of the natural system, in Linmeus 1 own opinion 

 the highest aim of botany, the task of their lives. The 

 key was given by the study of the order Ranunculacese in 

 the Jardin des Plaiites. In 17S9 Jussieu's System appeared. 

 It was not until 1815 that the natural system of Jussien 

 was received by the botanists of Philadelphia. In thai 

 year Abbe ( 'orrea published for the use of his class in 

 Philadelphia a reduction of the genera of Muhlenberg's 

 Catalogue according to the system of Jussieu. This was 



*1814. Pi T USH Flora Americce Septentrionalis, or a systematic arrant/* nn-nt 

 <ind di'scrijitio/i. <>f tlic plants of North America. London, 1 1 \ ols. 



flsis. \V. P. ('. I'.AI: TON Ciiinjifndiuin Flora' J'hi/<i'/, //,/! ica . rontninini/ a 

 description of the indigenous and na/ura/i:.rd ji/anr* /omul u-ithtn <i circuit often 

 iiiilcxaroiind rhilaih'lplnu. JMiiluiU'lphia. II vols. ,s. I. I'M- faro '-'.M p]i. II. L!:',l jip. 

 rum i!nlii-c<. 



; i^is. yiwiTAlli The Genera of North American I'/ants, and n cntaini/ne of 

 the sped IK ,,f tin- year /s;,\ riiilutleljihiu, II vols. 



