DISEASES OF PLANTS. 451 



rye, tall fescue, orchard grass, and Pna roinprcssu. Direct, inoculations on 

 wheat and barley gave negative results. 



An exaniination of timothy plants during the winter showed that the rust 

 mycelium winters over in the vicinity of the Arlington Experiment Farm, while 

 the teleutospore stage is more common in Pennsylvania and New York. The 

 jecidial stage is believed to be rare in the United States. 



The breeding work has indicated varietal resistance to the rust, although no 

 strains have been found that are entirely immune. 



Mycological studies upon wheat and wheat soils to determine possible 

 causes in deterioration in yield, T. D. Beck with (Abs. in Science, n. sen, 31 

 (J910), No. 803, p. 798). — Analysis of soils having failed to account for the 

 deterioration in yield, biological studies were made of wheat soils, comparing 

 them with virgin pi-airie soil. A number of organisms were obtained, among 

 them species belonging to the genera Colletotrichum, Fusarium, Macrosporium, 

 and Alternaria. 



To ascertain whether the spores of these fungi were normally present on wheat 

 stems, sections were made of the stems of wheat and placed in culture tubes. 

 After 5 days' incubation Colletotrichum. Macrosporium, Helminthosporium, and 

 Cephalothecium were found present in varying proportions. This series of ex- 

 periments showed the possibility of infection and that the spores were either 

 resting on the wheat plants or had already germinated. 



Another series of experiments was conducted in which the stems were 

 sterilized and then incubated, with the result that the fungi again were found 

 abundant. Finally culture experiments made from roots of wheat grown in old 

 wheat soil showed the presence of Colletotrichum, Fusarium, and Macrosporium. 



These experiments are believed to show that old wheat soil is infected with 

 certain fungi, that the spores or mycelium are found normally in or on the wheat 

 plant, and that a certain percentage of the wheat is pathologically infected with 

 these fungi, some of which also cause root infection. 



Floret sterility of wheats in the Southwest, E. C. Johnson {Abs. in Science, 

 ,1. ser., 31 (1910), No. 803, p. 792).— Attention is called to the floret sterility of 

 wheat, or the nondevelopment of the kernels in florets of otherwise normal 

 spikelets, as being especially common in Texas and Oklahoma. 



Investigations at San Antonio, Tex., showed from 30 to 50 per cent sterile 

 florets in wheat in 190S and from 12 to 15 per cent in 1909. An examination 'of 

 the sterile florets showed that they were almost invariably attacked by fungi, 

 Cladosporium graminHm and StemphyJium sp. being present. In addition rusts 

 were abundant, but the experiments show that the chief cause of the injury is 

 S. tritici. (See below.) 



Stemphylium tritici n. sp. associated with floret sterility of wheat, Flora 

 ^y. Patterson (Bui. Torrcij Bot. Club, 37 (1910), No. .',, p. 205). — A technical de- 

 ?crir)tion and a brief account are given of S. tritici n. sp., a fungus that appears 

 to be of considerable pathological importance, as artificial inoculations have 

 resulted in the production of 9 per cent of sterile florets. 



On the relationship of certain bacterial soft rots of vegetables, W. J. :Mokse 

 and H. A. Harding (Abs. in Science, n. ser., 31 (1910), No. 803, p. 791).— This is 

 an account of investigations carried on by the authors, the results of which have 

 been published elsewhere (E. S. R., 22, p. 649). 



Malnutrition diseases of cabbage, spinach, and other vegetables, Ij. L. 

 Harter (Abs. in Science, n. sen, 31 (1910), No. 802, p. 7 '/7).— This is a brief 

 abstract of studies by the author, a more extended account of which has been 

 noted elsewhere (E. S. R., 22. p. 147). 



Report of assistant in botany, R. Y, Winters (Florida 8ta. Rpt. 1909, pp. 

 LXXIX-LXXXV, figs, 12). — Dry Bordeaux mixture and air-slaked lime were 



