DISEASES OF PLANTS. 453 



In the genus Glomerella. A study was made of tiie material to determine tlie 

 presence of parapliyses, and on the basis of ttie abundant material the author 

 states that the genus Glomerella must in the future be considered as bearing 

 paraphyses. 



The author contrasts the characters of the perfect form of this anthracnose 

 with a number of others and concludes with a description of the perfect form, 

 to which the name Glomerella gossypii n. sp. is given. 



The blade blight of oats — a bacterial disease, T. F. Manns (Ohio Sta. Bui. 

 210, pp. 91-167, pis. 15, fig. 1). — A serious disease of the oat crop has been re- 

 ported in Ohio for several seasons. The author has made an extended study 

 of it and finds that it is chiefly due to bacteria. 



The disease is chiefly confined to oats, although a somewhat similar one has 

 been observed to a less extent on timothy and blue grass and on susceptible va- 

 rieties of wheat and barley. From the observations on timothy and blue grass 

 it is to be noted that the foliage suffers but little, while the culms are killed 

 above the upper joints. 



The preliminary effect of the disease is a yellowing, beginning either as small 

 round lesions on the blade or as long strealcs extending throughout the l)lade or 

 even the whole length of the culm and blades. The ultimate symptoms where 

 the disease has made much progress are a partial or general collapse of the 

 leaves, due either to the active lesions within the blades or a weakened vitality 

 of the plant. In advanced stages the^ affected leaves take on a mottled color, 

 sometimes becoming quite red. 



A study of the cause of the disease has shown that it is due to two species of 

 !)acteria acting in symbiotic relation ; one, a white organism to which the name 

 Pseudonionas avenw n. sp. is given, is apparently the most active, although a 

 second yellowish organism {Baeillus avenw n. sp.) is often present, and in prac- 

 tically all cases observed the two organisms were more or less abundant. 



The disease apparently spreads from the soil, and observations gained through 

 artificial inoculations as well as from conditions as they appear in the fields 

 indicate that there is opportunity for selecting resistant strains. 



Some fungus diseases of potatoes, F. Tidswell and T. H. Johnston {Agr. 

 Gaz. N. S. Wales, 20 (1909), Xo. 11, pp. 998-1012, pis. 8). — Following a general 

 description of the character of fungi and methods of their attack, the authors 

 give an account of the potato rot or late blight, early blight, dry rot, scab, 

 bacterial wilt, nematode injuries, and internal brown spot. Directions are 

 included for the preparation and application of fungicides for the control of 

 these diseases. 



Potato blig'lit and its treatment, D. McAiPiNE (Jour. Dcpt. Agr. Victoria, 

 7 (1909), No. 11, pp. 698-703, figs. 2 ) .—Attention is called to the potato blight 

 due to Phytophthora infestans and means are suggested for its prevention. 

 Among these treatments the author advises the treating of all seed tubers that 

 are suspected of being infected by the disease by subjecting them to dry heat 

 at 120° F. for 4 hours. This temperature seems to destroy the fungus and the 

 germinating power of the tubers is improved. In addition to the treatment of 

 the seed tubers, spraying the crop with Bordeaux mixture is recommended. 



The Fusarium wilt of cabbage, L. L. Hakter (Science, n. ser., 30 (1909), No. 

 782, p. 93Jt). — Attention is called to the wilt or yellows of cabbage, due to an 

 undescribed species of Fusarinm. This disease has been under investigation 

 in this Department for a number of years, having been first observed by 

 Smith in 1895. 



The more important symptoms of the disease are said to be retarded growth, 

 wilting of the foliage, and yellowing and dropping of the lower leaves. Later 

 the upper leaves are affected and drop off, leaving the stems bare. 



