DISEASES OF PLANTS. 645 



DISEASES OF PLANTS. 



A plant disease survey in the vicinity of San Antonio, Tex., F. D. Heald 

 and F. A. Wolf (U. S. Dept. Agr., Bur. riant Indus. Bui. 226, pp. 129, pis. J9, 

 fi(js. 2). — During 1909 and 1910 the authors made a plant disease survey of 

 a portiou of Texas included within a radius of 100 miles from San Antonio. 

 The object of the work was to determine the diseases which were prevalent 

 with a view to more detailed investigation of those which are either new or 

 imperfectly knowni. Especial attention has been paid to the diseases due to 

 bacteria, fungi, and other parasites, but those induced by environmental factors 

 have also been considered to some extent. After discussing the physiography, 

 soils, and climatology of the region, the different diseases are briefly described 

 under the headings of diseases of fruits, truck crops, field croi>s. forage plants, 

 trees and shrubs, ornamentals, and native plants. 



The smut fung'i of Switzerland, H. C. Scheu-enberg (Beitr. Kryptogamen- 

 flora Schicciz, 3 {1911), A'O. 2, pp. XLV+ISO, figs. 79).— This is a work intended 

 to have direct bearing upon the practical protection of plants, and gives (1) a 

 condensed account of the author's investigations on the smut fungi orf this 

 region and their spread, relations, and control; (2) a list of the local plants 

 subject to diseases in connection with their infecting fungi; (3) an alphabetical 

 index of hosts and one of fungi; and (4) an alphabetical list of authors, with 

 their writings in this connection. 



Cultures of Uredineae in 1911, J. C. Abthxje (Mycologia, 4 (1912), No. 2, pp. 

 Ji9-65; abs. in Science, n. ser., 35 {1912), No. 891, pp. 150, i5i).— This is an 

 account of the thirteenth year of culture work with rusts. Due to the unsea- 

 sonable hot weather many failures in inoculation were reported. 



Among the more important results during the year was the discovery of an 

 fecidial host for Gymnospomngium speciosum on Philadelphus, belonging to the 

 family Hydrangiaceie, the previous host plants belonging to the family Rosacese. 

 It was also found that both the Uromyces and Puccinia on Distichlis spicata 

 produce indistinguishable secidiospores on the same hosts. This together with 

 culture work has led to the conclusion that in some cases forms are placed in 

 the 2 genera which are not worthy of generic differences and scarcely entitled 

 to specific differences. They are held to represent races, or possibly varieties, 

 of 1 species rather than 2 species belonging to 2 genera. 



Variations in Grlomerella, C. L. Shear {Ahs. in Science, n. ser.,^35 {1912), 

 No. 891, p. 152). — The results are given of studies of various races, strains, 

 varieties, and species of Glomerella from 46 different host plants. 



Variations in morphological characters were observed and great variation in 

 physiological character was also found to occur. Most of the variations showed 

 no direct relation to the culture medium or other conditions of environment, 

 and more or less distinct races or strains were found to occur on the same host. 

 These strains maintained their principal characteristics in cultures as long as 

 they were grown. 



Plus and minus strains in an ascomycete, C. W. Edgerton (A6.s. in Science, 

 n. ser., 35 {1912), No. 891, p. 151). — In cultures of Glomerella cultivated from 

 the petiole of a cottonwood leaf in Louisiana the author has found that the 

 original culture has separated into 2 distinct strains, which he calls plus and 

 minus. The plus strain develops mature perithecia in masses occasionally, 

 these being identical with other species of Glomerella. The minus strain de- 

 velops the perithecia singly or in two's or three's, scattered over the medium. 

 When the 2 strains are grown on the same plate there is a well marked 

 boundary line where they come in contact. The author believes there is a 



