DISEASES OF PLANTS. 57 



upon tlie oxygen in the noil, and tliat the rooty, first stimulated into great activity by 

 the sulphate of ammonia, are deprived of the aVnindant sujiply of oxygen necessary 

 for their health. When running water is near, the oxygen is renewed from the 

 fresh water, and it is the oxygen rather than the moisture that is beneficial. — h. m. 



PIETERS. 



Beet-root tumor, M. C. Cooke {Jour. Roy. Hort. Soc. [^Londoii], 26 {1901), No. 1, 

 j)p. XLV, XL VI). — The presence of globose tumors of about the size of an orange, 

 on the side of beets, attached to the root by a narrow neck, is reported. When cut, 

 the substance of the tumor seems to be not unlike that of the root. It is believed to 

 be caused by the fungus (Edomyces leproides. Hitherto reported from North Africa, 

 it now is known to occur in England. So far there has been no production of spores, 

 and it is thought that this may be due to the effect of climatic conditions arresting 

 the growth. 



Disease in turnips and swedes, R. S. MacDougall ( lYons. Hirjldand and. Agr. 

 Soc Scotland, 5. ser., 14 {1902), pp. 244-263, figs. 6).— In August, 1900, the author's 

 attention was called to a disease of turnips and swedes that was proving very 

 destructive in the south of England. Upon examination it was found to be due to 

 bacteria {Pseudomonas destructans) , the disease being the same as that previously 

 described (E. S. R., 13, p. 467). The effect produced by the organism is described 

 at considerable length. The organism was isolated and cultivated through various 

 media, and by inoculation proved to be the cause of the disease. As possible means 

 of combating this rot the author recommends the destruction of diseased jilants, 

 lengthening the period of rotation, and rendering the conditions as favorable for 

 crop ])roduction as possiljlc 



The destruction of cell walls by bacteria, E. F. Smith {Ahs. in Science, n. ncr., 

 15 {1902), No. 376, p. 405). — Experiments are reported in which the destruction of 

 the inner tissues of the turnip by the organism Pseudomonas campestris is shown. A 

 study of diseased tissue shows that the bacterial masses occupy a considerable pro- 

 portion of the host when in advanced stages of destruction, and cavities are formed 

 by the solution of cell walls, some of them representing places formerly occupied by 

 hundreds of cells. The cells are crowded apart by the growth of bacteria, the mid- 

 dle lamella first disappearing, but in a short time the cell walls become very faint in 

 outline and finally disai)pear. 



Formalin treatment for grain smuts, R. S. Shaw {Montana Sta. Bid. 32, pp. 

 25, 26). — A brief report is given of results of 3 years' work with formalin for the 

 prevention of smuts of wheat, oats, and barley. Formalin has proved more easily 

 applied and more efficient than any other fungicide tested. It is used upon the seed 

 grain at the rate of 1 pt. of formalin to 40 galls, of water. The seed may be treated 

 either by dipping in the solution or sprinkling over piles of seed, the grain to be 

 well stirred to iiici-ease the thoroughness of application. 



Concerning the parasitism of Botryosporium, V. Pegliox {Ztschr. Pflanzen- 

 krauL, 11 {1901), No. 2-3, pp. 89-92). — The author reports the occurrence of the 

 fungus Botryosporium upon leaves of wheat grown in pots in the laboratory. A 

 study of the fungus seemed to show that it was identical with B. pidchrum. This 

 led to a study of the related species of the genus and their parasitic habits. The 

 author believes that a number of the species which have been described are iden- 

 tical. As a result of his inoculation experiments it is claimed that B. pidchrum can 

 only attack plants that have been weakened by nematodes or other causes. 



Disease of ginger in Jamaica {Bid. Bot. Dept. Jamaica, n. ser., 8 {1901), No. 11- 

 12, pp. 180-182). — A report is given of the disease which attacks ginger roots and is 

 known as the black rot. This disease is well known and may be recognized l)y the 

 sickly yellow foliage and black and decaying stems, and the rhizomes when dug will 

 be found black and decaying. Intelligent growers are said to dig up the affected 

 planta and the healthy ones growing near them and destroy them, also turning the 



