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186 !ME. G. BENTHA.*M OK ETJPnOHBTACE^. 



* 



Nomenclature, Systematic Arrangement, and Origin and Geogra- 

 phical Distribution. 



I. HISTORY. 



The Order may be said to have been established and defined by 

 Robert Brown ; but Adrien de Jussieu was the first to give any 

 good general view of the characters and natural arrangement of 

 the genera. His ' De Euphorbiacearum generibus Tentamen,' 

 published in 1824, evinces that correct appreciation of affinities 

 and clearness of method which distinguish all his monographs; 

 but the materials at his command were then exceedingly limited, 

 and, although several of his generic circumscriptions have been 

 too much neglected, yet the enormous additions since made to the 

 known species have really necessitated many important modifi- 

 cations of the system he proposed. After him Blume, in his 

 1 Bijdragen/ a remarkable work, exhibiting singular accuracy of 

 observation and judicious appreciation of genera considering the 

 restricted resources at his disposal in a distant colony, described 

 amongst others a considerable number of new forms of Euphor- 

 biacese. Klotzsch, of Berlin, seeing a large number of new Ame- 

 rican ones in the collections received from Sello and others, 

 bestowed much pains on their elaboration — but, unfortunately, 

 occasioned some confusion in the great number of new genera he 

 proposed, founded often on the examination of single species which 

 at first sight presented some peculiarity in their aspect. His 

 various papers, therefore, published chiefly in "Wiegmann's (Erich- 

 son's) ' Archiv ' and in the l Monatsberichte ' of the Berlin 

 Academy, and detached descriptions in various works, have not 

 contributed much to our general knowledge of the relations 

 which the different Euphorbiacese bear to each other. 



A number of detailed descriptions or cursory indications 

 of new species dispersed through a great variety of works 

 had further contributed to the difficulty of naming an Euphor- 

 biacea, or of determining whether it was new or not, w r hen Henri 



Baillon, working on the collections of various Parisian herbaria, 

 undertook a comprehensive view of the genera. This he pub- 

 lished in 1858 under the title of ' Etude generate du groupe des 

 Euphorbiacees.' This work showed a great deal of careful re- 

 search and accurate observation ; but its practical utility was much 

 marred by a want of method. It contains no well-defined tribes, 

 nor, indeed, any divisions, except twelve series (of which no charac- 

 ters are given), and no conspectus or short diagnoses of the genera 



