THE AMERICAN BOTANIST 39 



'here and there, but in the loose soil of that abandoned field, it 

 forms a rich mantle of white. In such neglected fields, too, 

 I have seen myriads of Erysimums, and the rush-like Lygodes- 

 mia, with beautiful, star-shaped heads of rose-purple, a plant 

 of sparse growth in a state of nature, springs up in lavish 

 abundance and assumes the role of a vile and almost ineradi- 

 cable weed throughout cultivated tracts near the Bad Lands. 



These phenomena might arouse a suspicion in our minds 

 that the plants in this region are not satisfied, as it were, with 

 their environing conditions, and are constantly on the lookout 

 for something better. And this, in a sense is true — the fact 

 holds good throughout all nature. All organisms are ever 

 ready, no matter how perfectly they may be adapted to their 

 conditions of existence, to welcome every new circumstance 

 that will give them an advantage in the struggle for exist- 

 ence. Thus, a plant that chanced to obtain a foothold in a 

 cultivated soil would not be compelled to battle so keenly with 

 other organisms for food and standing-room, nor with inor- 

 ganic nature, and therefore would have a much better show of 

 developing a large number of seeds, and thus work for the ad- 

 vancement of the species. 



The variety in nature, so grateful to our eyes, is an out- 

 come of this everlasting competition for something better that 

 obtains among plants and animals, as well as among men. 

 Now, Pine Ridge reservation being a diversified region topo- 

 graphically, 



"Within this limit is relief enough. 



Sweet bottom-grass, and high delightful plain, 

 Round rising hillocks, brakes obscure and rough, 

 To shelter thee from tempest and from rain ;" 

 and because the nature of the conditions changes rapidly from 

 creek-plain to hilltop, or as we travel from the sand-hills, 

 through the pine country, to the Bad Lands, it is not surpris- 

 ing that the flora is almost endless in diversity and in flower- 

 time surpasses in grandeur that of tropical regions. 



Knoxville, Tenn. 



