STATISTICS OF METASPERMAE. 749 



Upon comparing the preceding table with the general tables 

 of specific range on pp. 715-716, a number of instructive 

 points will be discovered. 



The trees of the Minnesota valley are much more distinctively 

 southern than the general population. They are also much 

 more distinctively eastern. This is readily noted by comparing 

 the per cents of totals, for each element of range, in the ' gen- 

 eral and the special tables. This southernness and easternness 

 is more marked in the case of the metachlamydeous trees than 

 of the archichlamydeous, but in either is in excess of the 

 southern and eastern per cents of the total taxonomic groups. 

 Conversely, the trees are decidedly less northern in their char- 

 acter than the general population. The Archichlamydeae are, 

 however, more northern than the Metachlamydeae. Of the 

 metachlamydeous trees a slightly larger percentage show the 

 western range than of the archichlamydeous trees. This is 

 due to the general lateral solidarity which has been pointed out 

 as a characteristic of the Metachlamydeae. 



The shrubs of the Minnesota valley present opposite range 

 characters, in comparison with the trees. They are more dis- 

 tinctly northern than southern and the northernness is in ex- 

 cess over that of the general population while the southernness 

 is considerably less. Between the eastern and western per cents 

 of the shrubby element and of the whole element there is less 

 difference, but the shrubs are a trifle more eastern in character 

 than the general flora. The northernness of the metachlamyde- 

 ous shrubs is more pronounced than the northernness of the 

 archichlamydeous shrubs, while the metachlamydeous shrubs 

 are both more eastern and more western than the archichlamy- 

 deous. This, again, is a result of metachlamydeous lateral 

 solidarity. The strong northernness of metachlamydeous 

 shrubs is the most remarkable feature of shrub distribution in 

 the valley of the Minnesota. It may perhaps be attributed to 

 the influence of the tensions upon habit. The shrubby habit 

 might be expected to emerge more strongly farthest from the 

 Central region. 



The herbs of the valley are distributed very much like the 

 general element. The differences bet ween the trees and shrubs 

 serve to neutralise each other and the residuum is only slightly 

 more northern, southern and western and only slightly less 

 eastern than the total flora. 



