DISEASES OF PLANTS. 547 



the result of nutritional deficiencies or disturbances, or both, and that the cor- 

 rection of these tends to restore the normal condition and productiveness of the 

 plant. Measures apparently effective in this connection are protection from 

 insect pests and frequent spraying with iron salts. 



Hiltner's experiments on the control of dry spot of oats, T. A. C. Schoevebs 

 (Tijdschr. Plantenziekten, 20 (1914), No. 2, pp. 69-73).— This is mainly a brief 

 revievsr of the work of Hiltner, above noted. 



Some observations on ordinary beet scab, B. F. Lutman and H. F. Johnson 

 (Phytopathology, 5 {1915), No. 1, pp. 30-34, figs. 4).— From a study of eight 

 organisms isolated from scabby beets from various parts of Vermont the authors 

 were led to the conviction that the forms were not only identical, but were the 

 same as the organism Actinomyces chromogenus, which causes potato scab. 

 This same organism is present in many soils and on many plants, but in ex- 

 planation of the scabbing of the potato and the beet, in connection with the 

 immunity of many other root and tuber plants, the authors hold that the 

 reason undoubtedly lies in the fact that some sort of a cambium is so close to 

 the surface as to be affected by the toxic substances produced by these bacteria. 

 The parasitism of the organism is said to be dependent on a particular type of 

 root or tuber structure, and when this is not present it is forced to live as a 

 saprophyte. 



Beet scab, Grimm (PraJct. Bl. Pflanzenbau u. Schutz, n. ser., 12 {1914), No. 

 8-9. pp. 100-102). — Beet scab is said to have caused loss in several localities, 

 particularly in connection with the wet season of 1913. The disease seems to 

 be due rather to bad nutritive conditions than to parasites primarily. The use 

 of seed in propagation and the employment of potassium, superphosphate, and 

 ammonia in fertilizers is recommended. 



Bearing beet nematodes on agar, E. Berliner and K. Busch {Biol. CentU., 

 34 {1914), No. 6, pp. 349-^56, pi. 1).—A brief account is given of the rearing of 

 nematodes (Heterodera schachtii) on rootlets of various seedlings grown on 

 agar, and of the changes and activities observed. None developed apart from 

 the rootlets or survived long after the exhaustion of the reserve material which 

 was brought forward from the egg stage. 



Root scab and other celery diseases, H. M. Quanjeb and N. Slagter 

 {Tijdschr Plantenziekten, 20 {1914), No. 1, pp. 13-27, pi. i).— The authors' con- 

 clusions from studies as described with rust or scab of celery root are said to 

 have confirmed those of Klebahn (E. S. R., 22, p. 746) that Phoma apiicola is 

 the cause of this disease. It is thought, however, that infection with this fun- 

 gus from the seed is rather exceptional, the rule being that the infection is 

 due to material in the soil, fertilizers, etc. Formalin was a very helpful treat- 

 ment in this connection for the seed bed. 



As regards Septoria apii, associated with celery leaf spot, Klebahn's conclu- 

 sion regarding the agency of the seed as a carrier of infection was confirmed. 

 This trouble also was largely prevested by the formaldehyde treatment and 

 benefited by the use of Bordeaux mixture applied to the leaves. 



Some new bacterial diseases of legumes and the relationship of the 

 organisms causing the same, T. F. Manns {Delaware Sta. Bui. 108 {1915), 

 pp. 44, pis. 20, fig. 1). — ^An account is given of a disease of sweet pea due to 

 Bacillus lathy ri, a previous account of which has already been noted (E. S. R., 

 29, p. 352) ; and similar diseases upon clovers, garden beans, and soy beans are 

 described. 



The disease on sweet pea is apparently widely spread, having been reported 

 in England, Massachusetts, Maine, New York, Delaware, and also in Ireland. 

 Previous investigators have referred to a number of causes, but the investiga- 



