242 



The Kant Wofctft. 



hitherto scarcely thought of as possible. The new forms are 

 reported to be fully constant from seed, as much so or more than 

 the parent forms, which were very constant. The possibilities 

 of accidental seed mixing, the effect of vicinism and cross polli- 

 nation are considered as nil, as every possible precaution had 

 been taken with the different varieties that mutated. It is 

 suggested that the change is not due to the direct action of the 

 cold but to the effect of warmth upon the green portions of the 

 plant while the roots remained frozen. If any mutations of the 

 above sort are possible, there are plenty of opportunities in this 

 country to observe them. 



L. R. Waldrox. 



Some Unsolved Problems of the Prairies, with special refer- 

 ence to the prairies of Illinois, are formulated by Henry A. 

 Gleason in a recent issue of the Bulletin of the Torrey Botanical 

 Club. Their successful study, the author points out, involves 

 reconstruction by means of books of travel and description, 

 lists prepared by botanists of a past generation, areas of limited 

 extent on which prairies are still preserved, and comparisons of 

 prairies farther west as described by present-day ecologists. 



Some of the questions proposed are : 



1. What were the conditions, climatic or of other nature, 

 at the close of the glacial epoch, which led to the invasion of 

 prairie plants from the west rather than forest plants from the 

 southeast? Emphasis is laid upon the accumulated effect of 

 centuries of arid climate in the southwest, from which the 

 plants of the prairies immigrated, as efficient in causing the 

 treelessness of our prairies. 



2. The flora of the prairies of the Wisconsin glaciation in 

 the northern part of Illinois is very different from that of the 

 Ulinoisian glaciation at the south, estimated to be eight times as 

 old. Does this flora at the south indicate the survival of a pre- 

 Wisconsin interglacial flora, which persisted during the Wiscon- 

 sin period, or an invasion of prairie species from a different direc- 

 tion or at a different time, or merely an adaptation to different 

 conditions of soil, temperature, or other factors? 



3. The aquatic plants surrounding the sloughs and ponds 

 of the prairie were generally of broad distribution, or at least 



