STATISTICS OF METASPERMAE. 738 
The third table of the series showing the North Ameri- 
ean range of extra-continental Minnesota valley metas- 
permic species and varieties presents some interesting per- 
centages. Of the total element 85.9 per cent are northern and 
50.7 per cent southern in North America. Comparing with 
the general tables of the entire flora, we find that 55.6 per cent 
of the species are northern while 76.1 per cent are southern. 
This indicates the predominent northern character of the extra 
continental specific element. Its presence in the Min- 
nesota valley is therefore principally to be referred 
to the influence of the Conifer region of Engler or the 
Northern of Drude, which lies just above the latitude of the 
Minnesota valley. Of the extra-continental element 93.3 per 
cent. is eastern and 75.4 per cent. western. Comparing again 
the tables for the entire metaspermic flora we find that 87.2 per 
cent. are eastern and 51.4 per cent. western. The difference be- 
tween the general percentages is therefore greater than be- 
tween the extra-continental percentages. This indicates a 
more general latitudinal distribution of extra-continentally 
ranging species than of the average species of the valley. 
Since, however, this extra-continentai element is so preponder- 
antly northern the longitudinal distribution is not equal to the 
average longitudinal distribution. The extra-continental ele- 
ment is therefore distinctively lateral rather than vertical in 
its charactistic inter-continental distribution. 
Besides the comparison of totals, the comparative distribu- 
tion of the three taxonomic groups will be worth a moment’s 
attention. Of the total specific elements the Monocotyledones 
run 68.2 per cent.northern, 69.1 per cent. southern, 93.6 per cent. 
eastern, 53.1 per cent. western. Of the extra-continental ele- 
ment the Monocotyledones run 86.2 per cent. northern, 47.4 
per cent. southern, 93.9 per cent. eastern, 76.7 per cent. western. 
These figures indicate for the extra-continental Monocoty- 
ledones an increase in average northernness and a decrease in 
average longitudinal equality of distribution, together with an 
increase of lateral equality of distribution. 
Of the total specific elements the Archichlamydeae run 55.9 
per cent. northern, 75.1 per cent. southern, 86.1 per cent. east- 
ern, 49.6 per cent. western. Of the extra-continental specific 
element the Archichlamydeae run 83.1 per cent. northern, 50.0 
per cent. southern, 93.0 per cent. eastern, 70.7 per cent. west- 
ern. These figures preserve an exact parallelism with those of 
the Monocotyledones, but with varying internal ratios. The 
