1895,] Botany, 487 
one hundred and forty-one trees and shrubs which grow naturally 
within our borders, all but about twenty-five have migrated from the 
east, in nearly all cases following the streams. Of these twenty-five, 
about four or five may be considered strictly endemic, the remainder 
having come down from the mountains. In several expeditions made 
by members of the “ Botanical Seminar” along the Missouri River 
from the southeast corner of the State to the mouth of the Niobrara 
River, it was found that many species of trees and shrubs are confined 
to limited areas in Richardson and the adjoining counties, (in the ex- 
treme southeastern corner of the State) and that the number of species 
decreases with a good{deal of regularity as we ascend the river. The 
same general law is seen as we ascend the three great rivers, the Repub- 
lican, Platte and Niobrara, which cross the State from west to east. 
On the other hand, as we ascend the streams, we meet here and there a 
mountain tree or shrub }which is wandering eastward down the slope 
from an elevation of a mile above sea-level, in the western counties, 
to less than a thousand feet along the Missouri River. Thus the Buf- 
falo Berry, Golden Currant, Low Sumach, the Dwarf Wild Cherry, 
and Yellow Pine |have travelled half way or two-thirds across the 
plains; while the Creeping Barberry, Greasewood, Black Cottonwood, 
Rydberg’s Cottonwood, Mountain Maple, Mountain Mahogany, and 
Sage Brush barely enter the western counties, not extending eastward 
of the Wyoming line more than a few miles. A couple of species of 
Wild Roses, the Sand Cherry, and, perhaps, the Sand Plum, appear to 
belong strictly to the plains. . 
The grassy vegetation, and the other herbaceous plants present a 
similar commingling of eastern aud western species. Every mile which 
one advances to the westward brings him in contact with plants not 
hitherto seen, while at the'same time he leaves behind him some famil- 
iar species. I know of no other place on the continent where there is 
a finer illustration of the commingling of contiguous floras than is to - 
be found on the Nebraska Plains. Not a few of the herbaceous species 
in the southern half of the State have come up from the plains of the 
southwest, some, even, coming from Texas and New Mexico. Others, 
again, appear to have migrated from the great northern plains of the 
Dakotas, while here again there are endemic species, as the Buffalo 
Grass, Redfield’s Grass, False Buffalo Grass, and many of the more 
showy higher plants.—CHARLES E. Bessey. 
The Division of Agrostology.—A mong the things of botanical 
interest done by Congress, the establishment of the Divison of Agros- 
