DISEASES OF PLANTS. 747 



copper sulphate 5 minutes, then In lime water for 5 minutes. It is held that 

 the lower infection rate resulting when the wheat is sown late in soil that has 

 been moist for some time is usually due to the early germination and death of 

 the spores. Pot experiments are claimed to show, however, that spores germi- 

 nating in damp soil may produce germ tubes terminated by secondary spores, 

 which may agnin produce elongated infection threads. 



Head smut of sorghum and maize, A. A. Potter (U. 8. Dept. Agr., Jour. 

 Agr. Research, 2 U9U), No. 5, pp. S39-S12, pis. 7, figs. 7).— An account is given 

 of the head smut of sorghum due to Soi'osporium reilianum. 



This fungus, it is said, was first reported from Egypt in 1868 and has been 

 found to be a destructive parasite of sorghum, and to occur also on maize. 

 The author has made a study of the organism grown in artificial cultures, and 

 a detailed account of its life history is given. It is stated that the work of 

 other investigators pointed to the conclusion that infection was by means of 

 seed-borne spores, but numerous floral inoculations failed to show that it could 

 be produced intraseminally and carried over in the seed to the next crop. On 

 the other hand, large percentages of infection were repeatedly produced by the 

 inoculation of seedlings with dry spore material. The author thinks that it is 

 clearly proved that the parasite is not carried with the seed, but is wind- 

 distributed in the locality in which it occurs, doubtless infecting the seedling 

 from the soil. 



But little appears to be known regarding the prevention of the head smut, 

 but as milo maize is immune, this could probably be grown in regions where 

 the other species of sorghum are subject to attack. 



A bibliography is appended. 



Some important contributions concerning the diseases of sugar beet plants 

 in 1913, A. Stift {Bl Zuckcrrubenbau, 21 (.191^), Nos. 5, pp. 12-15; 7, pp. 108- 

 111). — The author reviews some of the more important contributions pertaining 

 to the diseases of sugar beets due to nematodes, fungi, etc. 



Resistance in tobacco to hydrocyanic acid gas injury, J. Johnson (Phyto- 

 pathologij, 4 {19U), No. 2, p. iiS).— Attention Is called to the fact that fumi- 

 gation with hydrocyanic acid resulted in the discoloration and wilting of the 

 leaves of three varieties of tobacco, namely. Little Dutch, Cuban, and White 

 Burley, while Connecticut Broadleaf remained free from Injury in all parts of 

 the gi'eenhouse. 



Report of assistant plant pathologist, O. F. Bueger (Florida Sta. Rpt. 1913, 

 pp. LXXXVII-XCV, figs. 3). — The bacterial rot of lettuce, first reported some 

 years ago at this station (E. S. R., 21, p. .342), was present to some extent, and 

 an Investigation was carried on to determine the effect of aphids in the distri- 

 bution of the disease. Aphids were collected from an infected field and placed 

 on two healthy lettuce plants, and in about 12 days the infected plants were 

 reduced to a black putrid mass, seeming to indicate that the disease might be 

 carried in this manner. 



Notes are given on the lettuce drop, due to Sclerotinia Wbertiana, and a dis- 

 cussion is given of the relation of the fungus to atmospheric conditions and par- 

 ticularly that of temperature. 



A brief account is given of the bacterial rot of cucumbers, which has been 

 previously described (E. S. R., 30, p. 149), and notes on a number of vegetable 

 diseases, among them those of tomatoes, beets, celery, onion, and cantaloup. 



Fruit rot, leaf ?pot, and stem blight of the eggplant caused by Phomopsis 

 vexans, L. L. Haster {U. 8. Dept. Agr., Jour. Agr. Research, 2 {1914), No. 5, pp. 

 S31-338, pis. 5, fig. 1). — A report is given of a disease of eggplants that has been 

 variously reported as due to Phoma solani, Phyllosticta hortorum, and As- 

 cochyta hortorum. As a result of inoculation experiments and morphological 



