184 BOTANICAL GAZETTE , [February 



phytosociology being almost exactly the same as Cowles's 3 physiographic 

 ecology, while ecologic phytosociology corresponds very closely to Warming's 

 ecological plant geography. To floristic phytosociology would be referred not 

 only the enumeration of the flora of the associations, but also more exact 

 studies as to the importance of the species to the community, and the con- 

 stancy of the relationship. These relationships are discussed in detail by 

 Pavillard 4 in a more recent paper. One phase of this relationship has been 

 estimated in a quantitative manner by Braun-Blanquet, s by giving to each 

 species in an association a coefficient of affiliation (Gesellschaf tstreue) , the first 

 rank (5) being conferred upon species confined exclusively to the particular 

 association, and the lowest (o) belonging to ubiquists. To this Pavillard 

 adds another evaluation of the species, based upon its importance in develop- 

 ment and maintenance of the association, and expressed as its genetic coeffi- 

 cient, and here also the numerical value is also from 5 to o. Analyzed in such 

 a manner, the floristic composition seems to Pavillard decidedly the best 

 manner of characterizing an association. The characterization of the plant 

 association by floristic composition only is also insisted upon by Du Rietz 

 and his associates. 6 They also favor attention to priority in the use of eco- 

 logical terminology, a concession that ecological writers are not likely to grant. 

 Du Rietz contends that the Swedish school of ecologists is distinguished by the 

 use of true inductive methods as contrasted with the less desirable procedure 

 of other workers. He also proposes certain new terms of minor importance. 



Gams 7 is less modest in his demands, for he wishes to abolish the use of 

 formation, association, and most other synecological (or biocoenological) terms 

 now current, because they have been and still are being employed in different 

 senses by different writers. Instead of such fairly familiar terms, he would 

 substitute a new set founded to some extent on new concepts. He contends 

 that two types of units, the ecological and topographical, have been confused 

 and should be distinguished with care. The former he calls "synusia" 

 (associations), and distinguishes three grades where the component elements 



3 Cowles, H. C, The physiographic ecology of Chicago and vicinity. Bot. Gaz. 

 31:73-86. 1901. 



4 Pavillard, J., Remarques sur la nomenclature phytogeographique. Mont- 

 pellier. pp. 27. 1919. 



5 Braun-Blanquet, J., Eine pflanzengeographische Excursion durch Unter- 

 engadin und in dem schweizerischen National Park. Bericht. Schw. Bot. Gesells. 

 26:1-79. 1918. 



6 Du Rietz, C. E., Fries, T. C. E., and Tengwall, T. A., Vorschlag zur Xomen- 

 klatur der soziologischen Pflanzengeographie. Svensk. Bot. Tidskrift 12 :14s"" 1 7°- 

 1918. 



7 Gams, H., Prinziprenfragen des Vegetationsforschung. Ein Betrag zur Begriffs- 

 klarung und Methodik der Biocoenologie. Vierteljahrschr. Naturf. Gesells. in Zurich 



63:293-493- 1918. 



