NOTES AND COMMENT 



265 



Dr. H. A. Gleason, of the University of Michigan, has contributed 

 a paper to Torreya (Augu.st, 1913) on the relation of prairie fires to 

 forest distribution in Illinois. Dr. Gleason brings some additional facts 

 to the support of his belief that the middle western states were for- 

 merly more heavily forested than now and that forest fires have been 

 the chief cause of their recession to the scattered groves and belts 

 of the present time. The work of Professor Shimek on the prairies of 

 Iowa (see The Plant World: 15: 142) led him to the conclusion that 

 evaporation is the most imiDortant factor in retarding the advance of 

 the forest onto the prairie. The divergence of these views does not 

 necessarily form the ground for a controversy. It may well be that 

 evaporation is not so important a factor in this connection in Illinois 

 as it is in Iowa. In fact, it is to be expected that an artificial factor 

 such as fire would exert its maximum effect in disturbing natural vege- 

 tation near the transition region between two climatically controlled 

 areas, while \vithin these areas its effect would sink to a secondary 

 importance. 



To everyone who is interested in the broader aspects of agriculture 

 we would commend the publications of the International Institute of 

 Agriculture, at Rome. Their Monthly Bulletin, now in its fourth year, 

 is published in English and contains original articles, agricultural in- 

 telligence and statistics, and abstracts of literature much more extended 

 than those of the Experiment Station Record. The Bulletin, the Year 

 Book and the other publications of the Institute may be secured at 

 extremely reasonable rates of subscription. 



