404 ■ Flahault : Phytogeographic Nomenclature 



This is properly a same Formation in the primitive sense of the 

 word. Association alone is modified by dominant species and 

 with more or less extended variations that their absence or pres- 

 ence introduces into the relationship of members of the associa- 

 tion. Our " moors 7 of the north and west constitute a formation of 

 the same kind, where the dominating species may be either Callnna 

 vulgaris or Erica cinerca. Our " maquis M are of infinite variety, a 

 score of the 70 ligneous species of which they are composed may 

 be either dominant or subordinate according to local circumstances. 



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broad primitive sense given to it by Grisebach, and formations 

 such as he understood them later. The latter are associations 

 characterized by a physiognomic type instead of by dominant 

 species. But as the most prominent physiognomic type is more 

 often represented by dominant species, it often happens that for- 

 mation, so understood, corresponds perfectly to association as we 

 have defined it. 



Drude, Beck, Kerner, Warming admit the broad sense but 

 with various delimitations ; R. Hult, Stebler and C. Schrbter 

 agree to the narrower sense of the term. Others complying 

 with the same variations of the definition as Grisebach, have al- 

 lowed intermediate interpretations. 



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The result is that for some the definition of Formation answers 

 to a general type, as the Forest, while for others it has a special 

 import ; the forest then comprises a great many different For- 

 mations. 



This is not all. If in Grisebach's first definition, formation had 

 a purely physiognomic import, if the same word denotes an en- 

 semble of extended or restricted vegetation, the confusion is in- 

 creased on account of many authors wishing to give it a special 

 signification. 



Some, in fact, have reserved for formation a descriptive physiog- 

 nomic sense, while others, attempting to determine the relations of 

 cause to effect, gave to it a topographic or ecologic sense. For 



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plants determined by qualities of the soil ; there are therefore cli- 

 matic and edaphic formations. Some even interpose origin in the 

 definition of formation, as for example, Celakovsky regards a for- 



