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botany, — rules and practices whicli eliminate a deal of ver- 

 biage, facilitate comparison of views, and ensure mutual in- 

 tellio-ibility- Of botanical descriptions for the purposes of 

 systematic botany, it could be said that whatever is not clear 

 is not botany. May such clearness be hoped for in the future 

 of histological botany ? 



Chapter XII. treats of the unavoidable mixture of artificial 

 with natural grouping. Truly natural groups are often arti- 

 ficially defined, that is, are indicated by single characters ; 

 or truly artificial characters are used for the sake of con- 

 venience in the division of natural groups. Of the latter 

 sort are the divisions Polypetalce^ Gamopetalce^ and A2')etal(je 

 in Dicotyledons ; also those founded on the mode of curva- 

 ture of the embryo in CrucifercB, introduced by Brown, who 

 cautiously used them for genera, but raised to the rank of 

 primary or subordinal characters by De Candolle. Hypogyny, 

 perigyny, and epigyny are in the same category, and probably 

 no one w^as more sensible of it than Jussieu himself, whose 

 point and forte was the constitution of orders, not their col- 

 location under these artificial heads. De Candolle suggests 

 that, while to the more natural divisions are appropriated the 

 terms of Class, Cohort, Orders, Tribes, Genera, and Sections ; 

 such names as Division, Subdivision, Series, etc., might be 

 restricted to artificial divisions, and that these should take 

 adjective names not of generic origin, such as Licjuliflorm^ 

 Polypetalce^ and the like. 



Chapter XIII. relates to difficulties in phytography which 

 have grown out of various methods or absence of method in 

 the nomenclature of organs, and from the want of considera- 

 tion of the law of priority in such matters. The result of 

 which in some departments, such as histological morphology, 

 is a state of anarchy not unlike that which prevailed in the 

 names of groups before the days of Tournefort and Linnaeus. 

 "VYe may hope that order and lucidity will some day dawn 

 upon this chaos and a common language replace this confu- 

 sion of tongues. Meanwhile De Candolle offers certain coun- 

 sels, the utility of which, he says, is not doubtful nor the ap- 

 plication very difficult. 



