NOTES AND COMMENT 



The prize which was offered by The Plant World in November, 1915, 

 for the best paper in soil physics has been awarded to Dr. Howard E. 

 Pulling, of the Department of Plant Physiology of The Johns Hopkins 

 University, for a contribution entitled The Rate of Water Movement 

 in Aerated Soils. The giving of the prize was made possible by the 

 generosity of a friend of this journal who requested that his name 

 should not be used in connection with it. The judges were Mr. R. O. 

 E. Davis, of the Bureau of Soils, Prof. A. G. McCall, of the Maryland 

 Agricultural Experiment Station, and Prof. Charles F. Shaw, of the 

 College of Agriculture of the University of California. 



The first number of the Memoirs of the Gray Herbarium of Har- 

 vard University is devoted to A Monograph of the Genus BrickeUio, 

 by Prof. B. L. Robinson. Brickellia is a wholly American genus of 

 compositae with 91 species, 35 of which are found in the western United 

 States. This difficult group is treated in a most thoroughgoing manner, 

 with a discussion of the diagnostic value of the various features of habit 

 and structure which is calculated to inspire confidence in the deduc- 

 tions of the author. He remarks "No other feature offers in Brickellia 

 so many plausible grounds for distinctions as does the pubescence, 

 particularly the presence or absence of double pubescence, partly 

 glandular and partly non-glandular. Yet these characters, on further 

 examination and especially after the study of much material, nearly 

 always break down hopelessly and are seen to be subject to complete 

 intergradation ; and what is more significant appear in many cases to 

 be so readily changed .... as to render highly artificial any 

 distinctions based upon them." There is a strong suspicion lurking in 

 the vicinity of much of the taxonomic work of the present day that a 

 similar statement could be made for a great many genera in which 

 differences of pubescence have sufficed to establish specific distinctions. 



Prof. Herbert E. Gregory has pul^lished the results of his work on 

 the geography and water resources of the Navajo Country, in north- 

 eastern Arizona (Water Service Paper No. 380). This region, bounded 



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