DISEASES OF PLANTS. 983 



carendi'^hiaimm). The fungus is technically (le.«criV»erl and its effect on the host plant 

 shown. 



A pelargonium disease, G. Massee {Jonr. Roy. Ilorf. Soc. [London'], 27 [1902), p. 

 172; (lbs. in Bat. Centhl., 91 ( 1903), No. 1, p. 15). — A description is given of a rust of 

 Zonal Pelargoniums which is caused by Puccinia granulnrh. This fungus is said to 

 be not uncommon on various wild plants belonging to the family (ieraniacete and in 

 all probal)ility passed to imported cultivated forms from the indigenous si)ecies. 



Fairy ring- spot of carnations, P. Yoolino {E.vtr. from Ann. R. Accad. Agr. 

 Torino, 4o {1902), pp. 1-13, pi. 1; ahs. in Bat. Centhl., 90 {1902), No. 6, p. 16.5).— A 

 description is given of a disease which has been variously called smut of carnations, 

 fairy ring spot, etc., which is due to the fungus Heterosporkun cchimdatHm. The 

 author objects to the designation "smut," claiming that this name should be retained 

 for diseases caused by various species of Fstilaginefo. The pathological conditions 

 produced by the fungus are described as well as its spore formation and other charac- 

 ters. The fungus occurs in the leaves and results in the malformation of th(» flowers. 

 The disease develops rapidly and is readily reproduced arthicially, infections being 

 produced within a day or two. 



Preliminary eflEbrts to develop a continuous process of seed disinfection 

 by means of formaldehyde vapor, H. L. Bolley {Froc. Soc. Prom. Agr. Sci. 1902, 

 pp. 74-31, pi. 1). — In experimenting with formaldehyde as a disinfectant for seeds, 

 the author made a particular study regarding the disinfection of flaxseed, which, on 

 account of its nature, does not admit of soaking or sprinkling. For treating this seed 

 it is necessary to submit it to vapor, and passing the seed continuously through the 

 vapor was believed to give the Ijest results. Various forms of apparatus were devised, 

 which are figured and descriljed. The preliminary efforts made at disinfecting flax- 

 seed by means of formaldehyde gas are said to have produced good results. As to 

 the use of gas treatment upon other grain there seems to be little })ro])ability that 

 methods will be found less tedious or difficult than the simple method of sprinkling 

 with the fungicide. 



The use of the centrifug-e in diagnosing plant diseases, M. L. Uollev {Proc. 

 Soc. Prom. ^igr. Sci. 1902, pp. 32-35). — The author discovered while examining sam- 

 ples of grain in a centrifuge that this machine could be used for diagnosing plant 

 diseases. The method is quite simple. -It consists merely of placing a sample of the 

 seed grain shaken with distilled water in the tubes and exanuning the sediment 

 with a microscope. This method is so effective that spores of smuts could be detected 

 in samples of seed which would otherwise be pronounced free of all snuit. In a 

 study of flaxseed it was found that gasoline could be used in place of water to 

 considerable advantage. While examining the flaxseed for the wilt disease the 

 author found that in addition to the Fusarium lini a number of other fungi are almost 

 as constantly present as the Fusarium, and it is probable that they exert a consider- 

 able influence on the production of the flax wilt. In a study of flaxseed it was 

 shown that the spores of Fusarium lini are almost universally distributed throughout 

 the flax belt and were present in over 85 per cent of all samples examined. 



Early spraying as a means of protection against spring frosts, I.. Degki lly 

 {Prog. Agr. ef Vit. {Ed. UEst), 24 (1903), No. 9, pp. 257, ^:.V).— Heavy applications 

 of a solution of 40 to 50 kg. of iron sulphate in 100 liters of water made just before 

 the buds begin to swell are said to be beneficial in reducing various grape diseases 

 and also by temporarily checking the growth of grapevines to greatly lessen the 

 liability to late spring frosts. The effect is only temporary and growth is checked 

 for but a short time. Experiments are to be conducted to ascertain how long the 

 protective influence may be exerted. 



The reduction of lime in fungicides sprayed upon leaves, (i. K. ]\lAK(iiE'm 

 {Staz. Sper. Agr. Ital., 35 {1902), No. 11-1 J, pp. 922-925).— A discussion is given of 

 some of the changes that take place in the lime in Bordeaux mixture and other fun- 

 gicides when exposed upon leaves. 



