DISEASES OF PLANTS. 645 



of diseases on plants; and natural enemies of parasites and means of their 

 control. 



More than 500 cryptogamic forms, systematically arranged, are discussed, 

 also a few plant troubles due to phanerogamic parasites. The analytical key 

 includes the principal groups of parasitic fungi and the work concludes with an 

 index. 



The nature of fungus diseases of plants, J. R. Johnston {Porto Rico Sugar 

 Producers' Sta. Circ. 2 [English Ed.], pp. 25, figs. 9). — A popular account is 

 given of the causes of fungus diseases of plants, together with notes on their 

 effect on the hosts, methods of control, etc. 



Further cultures of hetercecious rusts, W. P. Fraser {Abs. in Phytopathol- 

 ogy, 3 {1913), No. 1, p. 73). — The author shows that 5 of the fern rusts 

 belonging to the genus Uredinopsis are hetercecious, having their fecidial stage 

 on Abies balsamea. 



Mycosphaerella pinodes the ascig'erous stage of Ascochyta pisi, R. E. 

 Vaughan {Abs. in Phytopathology, 3 {1913), No. 1, pp. 71, 72). — According to 

 the author's observations and experiments, the ascigerous stage of A. pisi is 

 M. pinodes. 



Effect of the steam-formalin treatment on certain soil organisms, J. R. 

 Winston {Abs. in Phytopathology, 3 {1913), No. 1, p. 7/f). — The author found 

 that with the steam-formalin treatment on soil infected with Fusarium from 

 tomato and Rhizoctonia from potato, pathogenic organisms were killed i:i about 

 one-half the time required by steam alone. 



Plant diseases in Virginia in the years 1911 and 1912, H. S. Reed and 

 C. H. Crablll {Virginia Sta. Rpts. 1911-12, pv- 35-50, figs. 13). — Information 

 relating to plant diseases in Virginia is given, the data being largely compiled 

 from blanks sent out to correspondents in different parts of the State. The 

 data are reported according to the alphabetical arrangement of the host plants. 



Review of diseases and injuries of cultivated plants, H. Morstatt {Pflan- 

 ser, 9 {1913), No. 4, pp. 184-194)- — This is a brief account of recent injuries to 

 cultivated plants by animals and higher parasites, as well as by various bacteria 

 and fungi. 



Helminthosporium diseases of barley in Wisconsin, A. G. Johnson {Abs. 

 in Phytopathology, 3 {1913). No. 1, pp. 75. 76). — According to the author, three 

 diseases of barley were observed in Wisconsin during 1912, caused by H. 

 gramineum, H. teres, and H. sativum. 



A study of the winter resistance of the uredospores of Puccinia coronata, 

 H. S. Reed and F. S. Holmes {Virginia Sta. Rpts. 1911-12, pp. 78-Sl, fig. 1).~A 

 report is given of studies begun in 1909 to determine whether the crown rust 

 of oats (P. coronata) is carried over the winter by the uredospores in the 

 vicinity of the station. The observations reported were made on two plats of 

 oats, one an area of volunteer summer oats, and the other a plat of winter 

 oats. Material was collected from time to time, and the viability of the spores 

 was determined by the hanging drop method. 



The data obtained indicate that the uredespores, under natural climatic con- 

 ditions, may and do retain their viability on winter oats and to a limited 

 extent upon volunteer summer oats. 



The relation of spore vitality to temperature is discussed, from which it 

 appears that in a general way the percentage of viable spores on the winter 

 oats corresponded to the temperature curves. 



Agar culture of wheat as a means of seedling purification, D. G. Milbeath 

 {Abs. in Phytopathology, 3 (1913), No. 1, p. 74)- — A preliminary report is given 

 of certain investigations on root diseases of wheat conducted at the North 

 Dakota Station. The purpose of the work is to ascertain by pure cultures the 



