APPLICATION OF THE QUANTITATIVE METHOD 221 



Specimen y 



Length blade upper leaf .... 155 mm. 



„ first empty glume . . . . 37 „ 

 „ flowering glume . . . 4*0 „ 



„ awn first flowering glume . . o „ 



Ratio length (ist empty) : (ist flowering) glume 0*93 „ 



The order in which the tables are used being arbitrary, I 

 begin this time with : 



Table V. : minimum, Agrostis probably excluded ; maximum, 

 Glyceria, Bromus and Festuca excluded [here the practical utility 

 of an empirical value (ratio) is obvious]. 



Table IV. : minimum, Agrostis again probably excluded ; 

 maximum, exclusion of Bromus confirmed, Alopecurus excluded. 



Table III. : minimum, exclusion of Bromus and Festuca con- 

 firmed ; maximum, exclusion of Agrostis confirmed. 



Since five species have been excluded, y is Melica uniflora. 



I try now a third Grass z and measure the primordia {one stem, 

 one spikelet). The figures are : 



Specimen z 



Length blade upper leaf .... 327 ram. 



first empty glume . . . . 3*2 „ 



„ flowering glume ... 5-2 „ 



„ awn first fliowering glume . . 17 „ 



Ratio length (ist empty) : (ist flowering) glume 0*62 „ 



I begin with Table I. : minimum, no species excluded ; 

 maximum, Melica, Glyceria, Agrostis, Alopecurus and Festuca 

 excluded. 



Table II. : minimum, Bromus excluded. 



All the species being excluded, it may be concluded that z 

 does not belong to any of our six species. In order to verify 

 this deduction, I take the tables in the reverse order, and begin 

 with : 



Table V. : minimum, Agrostis and Alopecurus excluded, 

 Melica very probably excluded ; maximum, Glyceria probably 

 excluded. 



Table IV. : minimum, Bromus excluded, exclusion of 

 Alopecurus confirmed; maximum, exclusion of Melica and 

 Glyceria confirmed. 



Table IH. : minimum, exclusion of Bromus confirmed ; 

 maximum, exclusion of Agrostis confirmed. 



Table II. : no more species excluded. 



Table I. : minimum, no species excluded ; maximum, exclu- 

 sion of Melica, Glyceria, Agrostis and Alopecurus confirmed, 

 Festuca excluded. 



