1918] 



DISEASES OF PLANTS. 147 



for 1916 showing the lumber, lath, and shingle cut by Provinces and by kinds 

 of wood. The value was, for lumber, $58,365,349 ; lath, $1,743,940 ; and shingles, 

 $5,962,933. 



Forest products of Canada, 1916. — Poles and crossties {Dcpt. Int. Canada, 

 Forestry Branch Bui. 62C (1917), pp. 8, figs. 2).— A statistical report on poles 

 and crossties purchased in Canada during 1916, with comparative data for 1915. 



DISEASES OF PLANTS. 



A textbook of mycology and plant pathology, J. W. Harshbebgee {Phila- 

 delphia: P. Blakistoti's Son d Co., 1917, pp. XIII+779, figs. 271).— This, book is 

 the outgrowth of the author's 27 years' experience as a teacher of botany, 

 during which time he condacted graduate courses in the morphology, classifica- 

 tion, and physiology of the fungi, and also courses in the methods used by 

 bacteriologists and mycologists. 



The arrangement of the material is that suggested by the needs of the class- 

 room and laboratory. The pi'incipal divisions of the text are mycologj% general 

 plant pathology, special plant pathology, and laboratory exercises in the cul- 

 tural study of fungi. In a series of appendixes the author gives formulas for 

 fungicides, spray calendars, keys for the determination of the genera and 

 species of a number of groups of fungi, and directions for the culture of mush- 

 rooms and for the collection and preservation of fleshy fungi. 



Plant diseases in Canada, H. T. GiJssow (Science, n. ser., 46 (1917), No. 

 1189, p. 362). — The author reports having observed in the Dominion of Canada 

 Dothichiza populea on Lombardy poplar, CoUetotrichum cereale on spring 

 wheat, and Lcptosphceria napi on the seed pods of turnips grown for seed. 



Noteworthy Porto Rican plant diseases, F. L. Ste\'ens (Phytopathology, 7 

 (1917), No. 2, pp. lSO-134). — Notes are given on a number of plant diseases ob- 

 served by the author in Porto Rico. 



Diseases and injuries of plants, J. Ritzema Bos (Meded. Rijks Hoogere 

 Land, Tuin en Boschbouivsch. [Wageningen], 11 (1917), No. 5, pp. 175-215, 244- 

 250). — The portions here noted include accounts of unfavorable or injurious 

 conditions affecting economic plants, such as inorganic agencies (weather, soil, 

 and spray injury'), animal parasites (including nematodes), cryptogamic dis- 

 eases, and causes of undetermined character. 



Pythiacystis related to Phytophthora, J. T. Babrett (Abs. in Phytopa- 

 thology, 7 (1917), No. 2, pp. 150, 151). — From a study of three strains of 

 Pythiacystis citrophthora, the author found close similarity of the oogonia, 

 oospores, and antheridia to those of Phytophthora cactorum. This marked 

 similarity is believed to indicate a close relationship between the two genera. 

 Puccinia glumarum, H. B. Humphrey (Phytopathology, 7 (1917), No. 2, pp. 

 142, 143). — Evidence is presented indicating that P. glumarum has been present 

 in America at least 25 years and possibly longer, and that it is not of recent 

 introduction, as previously reported (E. S. R., 33. p. 744). 



A new parasitic nema found infesting cotton and potatoes, N. A. Cobb 

 (17. S. Dept. Agr., Jour. Agr. Research, 11 (1917), No. 1, pp. 27-33, figs. 5).— 

 A new parasitic nematode which has been found infesting the tubers of the 

 potato, the feeding roots of camphoj", the rootstocks of violets, and the roots 

 of upland cotton is here described as Tylenchus penetrans. 



" External indications of the presence of the nema are the existence on the 

 roots or tubers of small, abnormal-looking areas, a few millimeters across, 

 sometimes in the form of pimples, but more often in the form of slightly sunken, 

 discolored areas. Each of these diseased areas when fully developed contains 

 up to about 50 specimens of T. penetrans in various stages of growth. 



