186 



SCIENCE. 



[N. S. Vol. XIV. No. 344. 



of Chicago, he enters the level prairies of Illi- 

 nois, originally treeless except along the water- 

 courses, and passes from these to the rolling 

 prairies of Iowa, whose undulating surface was 

 wanting in woody vegetation except in the 

 broad valleys which border the streams. Now, 

 as in Illinois, all over the landscape are lines 

 and clumps of vigorous trees, all the result of 

 man's work. What was once a treeless view is 

 now as freely dotted over with trees as in the 

 case of many a landscape in the originally 

 wooded portions of the eastern United States. 

 Crossing the Missouri River he soon enters the 

 region of the Great Plains, with an elevation 

 of 1,200 feet above the sea at the eastern border, 

 rising rapidly across Nebraska to 2,000, 3,000 

 and 4,000 feet above the sea. If he follows 

 the broad valley of the Platte River from 

 Omaha to Denver, he will receive the impres- 

 sion that the Plains are ' as level as a house 

 floor,' since he sees only the flat alluvial plain 

 worn by the great river, and is ignorant of the 

 fact that on each side are hills and valleys 

 stretching away for hundreds of miles, the hills 

 treeless as in the prairies, and the valleys with 

 groves of trees along the margins of the streams. 

 If he is fortunate enough to choose a route 

 which crosses the hills and valleys of the 

 Plains instead of following a single valley, he 

 will see for himself this relation of the trees to 

 the general surface of the country, and he may 

 even see evidence of the westward march of 

 the trees, where the fires no longer check 

 their growth. With the increase in elevation 

 the fringes of trees along the streams grow nar- 

 rower and narrower, until at last they disappear 

 altogether on the high plains at the foot of the 

 mountains, 4,500 feet or more above the sea. 

 This is the land of the 'sage brush,' 'dagger 

 weed,' ' buffalo grass,' ' bunch grass ' and ' cac- 

 tu.s. ' It is not a desert, and yet is as Uninviting as 

 one — until man runs little streams of water over 

 it, when as if by magic it is transformed into 

 a garden of flowers and fruits, or a farm of 

 golden wheat and purple alfalfa. What water is 

 to the plant is nowhere better shown than on 

 these high Colorado plains, a mile above the 

 sea. Then, still beyond, are the mountains, 

 with a vegetation entirely unlike that of the 

 plains at their base. Pines, spruces, firs, 



cedars are all of different species from those of 

 the east, and not many of the deciduous trees 

 are of species which are common along our 

 Atlantic border. For the botanist who sees this 

 flora for the first time it will be a novel experi- 

 ence to find that he can name scarcely a plant 

 that he sees, whether herb, shrub or tree. He 

 will need his collecting case and plant press, as 

 it will be impossible for him to resist the desire 

 to make specimens of the many interesting 

 plants he finds at every turn. 



THE SAND hills OF NEBRASKA. 



The interesting region known as the Sand 

 Hills of Nebraska may be visited by the botan- 

 ists who attend the Denver meeting in August. 

 They occupy an area of from 15,000 to 20,000 

 square miles in central and northern Nebraska, 

 having a width of from 100 to 200 miles. The 

 prevailing contour of the surface is irregular, 

 consisting of rounded, swelling hills with gentle 

 depressions between them, or elongated ridges 

 with steep sides, enclosing deep valleys. These 

 hills consist of sand or gravel, and when the 

 surface vegetation is removed the sand is driven 

 by the winds, and forms moving dunes. To a 

 very large extent the surface configuration is 

 such that the water which falls in the rains is 

 not drained off" in streams, but disappears in 

 the porous soil or evaporates from the surface. 

 Here and there are streams which find their 

 way through the valleys and hills, and where 

 these streams are of considerable size they have 

 worn deep canyons. Such streams are always 

 fed by many springs which burst out from the 

 sides of the canyons, and doubtless in this way 

 the water which falls upon the areas which have 

 no surface drainage finds its exit. 



The vegetation in the Sand Hills consists al- 

 most entirely of grasses and sedges intermingled 

 with deep-rooted perennial herbaceous or woody 

 plants. The perennial herbaceous plants are 

 coarse, strong-growing species, and the woody 

 plants are to a very large extent of low stature 

 and with large, widely-spreading roots. Among 

 these shrubs are the sand cherry {Primus bes- 

 seyi), shoe string (Amorpha canescens), one or 

 more species of prairie clover (Kvhnistera), one 

 or two species of wild roses (Rosa arkansana and 

 Eosaivoodsii), New Jersey tea (Ceanothus ovatus), 



