Notes and Brief Articles 



93 



Elliott, near Lamar, Arkansas, and an account of them published 

 in the December number of Phytopathology. The trees had been 

 heavily pruned and also grew on low, heavy soil. The parasitism 

 of the fungi was evident from the fact that the trees had made 

 a vigorous growth for one or two seasons following the cutting 

 back, and had been checked by the destruction, not only of the 

 heartwood of the older parts of the trees, but of the sapwood 

 as well. 



The campaign for the control of stem-rust of wheat through the 

 eradication of the common barberry has aroused a widespread and 

 effective sentiment against the shrub. This has resulted in the 

 actual removal of the following estimated percentages of the 

 plants located by a survey conducted by the United States De- 

 partment of Agriculture : Northern Illinois, 60 per cent. ; Wis- 

 consin, 90 per cent. ; Minnesota, 80 per cent. ; North Dakota, 90 

 per cent. ; South Dakota, 80 per cent. ; Nebraska, 75 per cent. ; and 

 Iowa, 75 per cent. 



Studies in the Mosaic Diseases of Plants by George W. Frei- 

 berg, published in the Annals of the Missouri Botanical Garden 

 for April, 191 7, contains many conclusions, among them the fol- 

 lowing : ( I ) Mosaic diseases are not caused by an unbalanced in- 

 organic nutrition. (2) The infectious substance is an enzyme and 

 not a "virus." (3) The reproduction of the mosaic enzyme can 

 be accounted for on purely physiological grounds, but the factors 

 which originally induced its formation are still unknown. 



The Laboratory of Forest Pathology of the Bureau of Plant 

 Industry, U. S. D. A., Dr. James R. Weir in charge, has been 

 removed from Missoula, Montana, to Spokane, Washington, 

 where it will be permanently installed in a fire-proof building. 

 The most intensive work of this laboratory isi centered in the 

 great white pine forests of Idaho. To promote pathological in- 

 vestigation in this region, a permanent field station will be estab- 

 lished; al'S'o a forest pathological museum. 



