OLDER SYSTEMS OF CLASSIFICATION. 



603 



Plants. A. P. De Candolle 1 (1778-1841) in his Theorie Elementaire de la Botanique, 

 ou Exposition des Principes de la Classification naturelle (published 1813), dis- 

 tinguished between cellular and vascular plants (Cellulares and Vasculares). The 

 former are constructed of cells alone, whilst in the latter vessels also are 

 met with. The cellular plants were divided into those without leaves (Cellu- 

 lares aphyllse) and those provided with leaves (Cellulares foliacese). The 

 vascular plants were divided according to anatomical views current at the 

 time into those in which the vascular bundles were scattered through the stem 

 and were supposed to originate from within (Endogense), and into those in which 

 the vascular bundles were arranged in a ring and were added to from without 

 (Exogense). The group Endogense included the Vascular Cryptogams (Endogenae 

 cryptogamse), forms destitute of flowers, and the Monocotyledons of de Jussieu 

 (Endogenae phanerogamse). The Exogenae, the equivalent of de Jussieu's Dicoty- 

 ledones, were divided into those with a simple perianth (Monochlamydeaa), and 

 those with a distinct calyx and corolla (Diplochlamydeae). The latter are further 

 subdivided into three groups: the Corolliflorae, in which the petals are united 

 into a continuous corolla; the Calyciflorse, in which the petals are inserted upon 

 the calyx; and the Thalamiflorse, in which the petals are free and inserted upon 

 the floral receptacle. Although De Candolle based his system upon characters 

 essentially different from those used by de Jussieu, and although in both systems 

 there are many deviations in the limitations of the classes and families, there is 

 on the whole an agreement in many essential particulars. Especially may we 

 note the recognition of Monocotyledons and Dicotyledons (though under different 

 names) as the two contrasting main divisions of Flowering Plants. And further, 

 that the Cellular and Vascular Cryptogams are sharply distinguished from 

 one another. The main groups, the Cellular and Vascular Cryptogams, the Mono- 

 cotyledons and Dicotyledons, are met with (under various names) from this time 

 onwards in all later schemes of classification; and, so far as we can tell, appear 

 to constitute so many natural groups groups, that is, of which the members 

 are all more nearly allied by descent to one another than to the members of the 

 other groups. 



Following De Candolle many Botanists elaborated schemes of classification 

 during the first half of the nineteenth century; these included Reichenbach, Oken, 

 Agardh, Martius, Brongniart, Bartling, Endlicher, Lindley, and many others. To 

 the non-botanist, recognizing the fact that there can be but one real natural system 



i A. P. DE CANDOLLE'S SYSTEM. 



I. VASCULAR OR COTYLEDONOUS PLANTS. 

 1. EXOGEN.E OR DICOTYLKDONS. 



A. Perianth double (calyx and corolla). 

 Thalamiflorse (petals distinct, inserted on 



the receptacle). 

 Calyciflorse (petals free and inserted on 



the calyx). 

 Corolliflorse (petals united together). 



B. Monochlamydese (perianth simple). 



VASCULAR OR COTYLEDONOUS PLANTS 



(continued). 

 2. ENDOGKNJ3 OB MONOCOTYLEDONS. 



A. Phanerogams (=true Monocotyledons). 



B. Cryptogams (= Vascular Cryptogams and 



Naiadaceae). 



II. CELLULAR OR ACOTYLEDONOUS PLANTS. 



A. Foliacese (leafy = Mosses and Liverworts). 



B. Aphyllse (not having leaves =Thallophy tes.) 



