TORREYA 



December, 1918 

 Vol. 18 No. 12 



A SKETCH OF PLANT CLASSIFICATION FROM 

 THEOPHRASTUS TO THE PRESENT 



By Alfred Gundersen 

 (Continued from November Torreya) 



Nineteenth Century 

 Augustin Pyrame de Candolle, of Geneva, greatly improved 

 the limits and arrangement of families (then called orders). 

 He increased their number to 161, as compared with Linnaeus's 

 67 and Jussieu's 100. Related families were called cohorts. As 

 the conifers have more than two cotyledons, he adopted the 

 term exogens instead of dicotyledons. His classification proposed 

 in 1813 was: 



r Exogenae (Diplochlamydeae and Monochla- 

 Vasculares -| mydeae) 



[ Endogenae (Phanerogamae and Cryptogamae) 

 Cellulares (Mosses, Algae, Fungi) 



The Monochlamydeae included the present gymnosperms and 

 catkin-bearing dicotyledons. "I place dicotyledons first," he 

 writes, "because they have the greatest number of distinct and 

 separate organs. Then as I find families where some of these 

 organs become consolidated, and consequently seem to disap- 

 pear, I refer them to a lower rank. But let no one imagine I 

 attach the least importance to the arrangement." The publi- 

 cation of the great Prodromiis was continued for fifty years. 



In Germany the Linnaean system was opposed by Schleiden, 

 who called the productions of the Linnaean school "hay." 

 Nageli urged that the important thing is to make every concep- 

 tion find its place in connection with the rest of knowledge; he 



[No. II, Vol. i8 of Torreya, comprising pp. 213-230, was issued 16 December 1918) 



231 



'i^i 



