640 METASPERMAE OF THE MINNESOTA VALLEY. 
From the table above it appears that the cosmopolitan gen- 
era of the Monocotyledones, form a larger percentage of the 
total Monocotyledones than do the cosmopolitan genera of the 
other two taxonomic groups. Passing to the extratropical 
genera, we find results similarly in line with those determined 
from the families. 
6. The Extratropical Generic Element. 
No. of |Per cent. of all] Extratropical 
genera.| Extratropical. |per cent. of each. 
Monocotyledones ............ 16 26.0 15.2 
Archichlamydeae............. 30 49.1 We 
Metachlamydeae............. 15 24.5 ae ere 
Totai Extratropical......... 61 Mak Satin Rédoped heen deuagsen cans 
Extratrop. perct. ofall genera [Dal |paceos case seiah eehakiee wees tee 
Here it is to be noted that the extratropical percentage of 
the Archichlamydeae exceeds the same percentage in the 
other taxonomic groups. Continuing with the tropical and 
subtropical element, the next table may be examined: 
7. The Tropical and Subtropical Generic Element. 
No. of Per cent. of all) Tropical and 
; Tropical and |jSubtropical per 
genera.’ Subtropical. | cent. of each. 
Monocotyledones............. 16 32.0 15.2 
Archichlamydee. ...........| 25 50.0 14.8 
Metachlamyde®.............. 9 18.0 7.0 
Total Tropical and Subtrop| 50 |.... 2.2.22... c [esse aeee ees faanes 
Tropical and Subtropical per 
cent. of all genera. ........ POG || cts ees ate uelemadetws ede 
An interesting variation from the results of family-examina- 
tion is apparent in the table above. In the central realm ele- 
ment the monocotyledonous influence is more distinct by 
genera than is the metachlamydeous. By families, it will be 
