Diseases of plants. 647 



For the control of the loose smut of wheat by the application of hot air with- 

 out any appreciable injury to the gerniinatiuf? power of the plant the jirain 

 should be soaked for from 4 to 6 hours in water at 20 to 30° C, and then 

 dried for from 20 to 30 minutes at a temperature of 55 to 00°. A lower tem- 

 perature duriii!; the soaking will require a longer soaking period. 



Plasmodiophora brassicse parasitic on melons, celery, and garden sortel, 

 E. F. L. Marchand (ComiJt. Rend. Acad. Sci. [Paris], 150 (1910), No. 21, pp. 

 1348-1350; abs. in Rev. Ilort. [Paris], 82 {1910), No. 12, p. 272).— The roots of 

 melons (cantaloups) planted on ground previously grown with cauliflower 

 showed enlargements similar to those produced by the club root of cabbage. 



On examination the diseased tissues were found to contain the Plasmodia and 

 spores of P. hrassicw, but the spores were about twice the normal size of those 

 found in the tissues of the cauliflower. This is due, it is claimed, to the suc- 

 culent tissues of the host and to the very favorable environment for the devel- 

 opment of the parasite. Growing with the vines were young celery plants and 

 garden sorrel {Rumex patientia), the roots of which were also found to be 

 malformed by the attacks of this parasite. 



Club root of cabbage and allied plants. W. H. Lawrence (Wasliiiif/ton Sta. 

 Bill. 5, spec, scr., p. 11, figs. 8). — On account of the gradual dissemination of 

 this disease in the Puget Sound country by means of seeds, plants, and in other 

 ways, gardeners and dairymen are w^arned against it, and a general description 

 of its characteristics and methods of control are given, together with the 

 results of inoculation experiments. 



Clover sickness and phosphorite, P. Kossovicii {Vyestmk Riiss. Selsk. Khoz., 

 1909, Nos. 2-'i-26; abs. in Zhur. Opuitn. Agron. (Russ. Jour. Expt. Landw.), 

 10 {1909), No. 5, pp. 692, 693). — ^As a result of experiments conducted on 

 chernozem soils the author found that the phosphoric acid of phosphorites was 

 not available and only that obtained from Thomas slag and superphosphates 

 was utilized by clover plants. 



The smut of maize and its treatment, D. McAlpine {Jour. Dept. Agr. Vic- 

 toria, 8 {1910), No. 5, pp. 290-298, figs. 11).— It is claimed that the common 

 corn smut of Australia is the head smut of maize { Soros porium reilianum), 

 and that the American corn smut {UstUago zew) has not yet been found there. 



The Australian smut attacks mainly the cobs and tassels, and the mode of in- 

 fection is through the young seedlings by means of spores adhering to the grains, 

 as was shown by infection experiments. Seed disinfection by means of copper 

 sulphate or formalin was found effective in controlling the disease. 



Studies on potato fusaria, O. Appel and W. Wollenweber (Mitt. K. Biol. 

 Land u. Forstw., 1910, No. 10. pp. l.'f- 16). —This is a further discussion (E. S. 

 R., 23, p. 148) of the morphology and biology of the genus Fusarium, with spe- 

 cial reference to the pathogenic possil)ilities of some of its species. 



Notes on the life history of Phytophthora infestans, D. McAlpine {Ann. 

 Mycoh, 8 {1910), No. 2, pp. 156-166, pi. 1; ahs. in Queensland Agr. Jour.. 25 

 (1910), No. 1, pp. 32-3.'i, pi. 1). — In a series of experiments with this fungus 

 sound potato tubers were infected! l)y contac-t with the disease<l tubers, by 

 means of sporangia, and by sporangia from diseased tomatoes. Ilealtliy tomato 

 fruits were also infected iiy sporangia from diseased i)otatoes and tomatoes. 



It was also shown that (1) the fungus may pass through all the st:iges in its 

 life from sporangia to sporangia in about 7 hours, (2) the mycelium under 

 ordinary conditions may produce sporangia in from 42 to 45 hours and in the 

 case of tomatoes in alxmt 7 hours. (3) the formation of sporangia is prevented 

 by a dry heat of 27° ('.. (4) sporangia lose tlieir vitality in 2<t hoiu-s if kept 

 dry, (D) zoospores are incapable of germiuatiou if kept dry fur 24 hours, and 



