186 SYSTEMATIC BOTANY. 



De Candolle's System. Aug. Pyrame De Candolle endeavoured 

 to classify the Vegetable Kingdom on principles more in harmony 

 with the knowledge of the structure of plants accumulated since 

 the promulgation of Jussieu's System. De Candolle's System has 

 become very generally used, on account of its having been adopted 

 in the great Descriptive work which he commenced, the ' Prodromus 

 Systematis Naturalis K-egni Vegetabilis/ a description of all known 

 species of plants. His subdivisions of the Exogens (or more pro- 

 perly Dicotyledons) are retained in many works. They are artificial, 

 like the "Classes" of Jussieu, but are, like them, convenient for the 

 distribution of the families into groups of manageable dimensions. 

 They are four in number, and founded on characters of the floral 

 envelopes, viz.: 1. THALAMIELOE^E, in which the petals are distinct 

 and (like the stamens) inserted on the receptacle (hypogynous) ; 

 2. CALYCIFLOR^E, with the petals distinct or coherent and (with the 

 stamens) inserted on the calyx (perigynous) ; 3. COROLLIFLOILE, 

 with the petals coherent, and inserted on the receptacle (the stamens 

 being inserted on the corolla) ; and, 4. MONOCHLAMYDEJE, or plants 

 with a perianth or a single circle of envelopes. 



In De Candolle's enumeration of the families, which had greatly 

 increased in number from Jussieu's list, the reverse order of 

 sequence is followed, the higher plants standing first. As regards 

 this point, however, it is a misconception to place the Thalamiflorce 

 first among the Dicotyledons, since they are manifestly inferior to 

 the Calyciflorce, and even to the Corolliflorce. 



During the last forty years a great many attempts have been 

 made to distribute the Orders more satisfactorily into Classes and 

 primary Divisions. Endlicher, Bartling, Meisner, Brongniart, 

 Lindley, and many other authors have published Systems of their 

 own. 



Endlicher's System. That of Endlicher has been extensively 

 used, and, moreover, is the basis of arrangement in his great 

 * Genera Plantar um.' 



Begion 1. Thallophyta. Sect. I. PEOTOPHYTA; II. HYSTEEO- 



PHYTA. 



Region 2. Cormophyta. 



Sect. III. ACEOBRYA. Cohort I. Acrobrya anophyta; 2. 



Acrobrya pro:ophyta ; 3. Acrobrya hysterophyta. 

 Sect. IV. AMPHIBEYA. V. ACEAMPHIBEYA. Cohort 1. G-ym- 

 nospermese ; 2. Apetalae ; 3. G-amopetalee ; 4. Dialype- 

 talae. 

 The cohorts are subdivided into classes, and these again into orders. 



