DISEASES OF PLANTS. 677 



specimens. On account of the blackening at or near the surface of the ground the 

 name blackleg has been given this disease. From recent publications the author is 

 led to believe that this disease is similar to a disease in this country attributed to 

 Rhizoctonia sob mi. 



In the specimens examined a white mold was found present which the author 

 thinks probably was a saprophyte, but he records its occurrence and gives a descrip- 

 tion, so that future investigators may determine whether it has any relationship 

 with the disease. 



Notes on the mosaic disease of tobacco, Bouygues and Perreau (Comj)t. Rend. 

 Acad. Sci. [Paris], 139 {1904), No. 4, pp. 309, .WO).— While investigating the mosaic 

 disease of tobacco in L903 the authors observed a few plants here and there that 

 appeared free from infection among a large number of diseased ones. Thinking per- 

 haps they had acquired some immunity, these apparently sound plants were trans- 

 ferred to a hotbed and kept under observation. Of over 200 such plants all became 

 affected but about 4 per cent. From these all the flowers were removed except two 

 buds on the healthiest and most vigorous plant. These were protected from foreign 

 pollen and their seed saved. 



In 1904 the seed was sown in a hotbed of new soil, and all fertilizers were excluded 

 which could have become infested with the disease through tobacco leaves, stems, 

 etc. From this bed 102 plants were selected, planted in a field, and given careful 

 culture, and by July 19 only about 2 per cent showed any indication of disease. 



This seems to indicate that partial immunity was secured during the first genera- 

 tion, as many of the plants remained free from disease throughout the season, 

 although their leaves were in contact with badly infested ones. However, if the 

 leaves became punctured in any way, the characteristic mosaic spots appeared. 



The authors believe that the losses caused by the mosaic diseases of tobacco may 

 be greatly reduced by the selection of seed from disease-resistant plants, placing the 

 seed beds in new soil, avoiding the use of composted tobacco stems and leaves, care- 

 ful cultivation to prevent injuring the plants, and the immediate removal and burn- 

 ing of ail diseased plants whenever observed. 



The breeding experiments are to be continued. 



Cluster cups on anemones, G. Massee.( Oard. Chron., 3. ser., 36 (1904), No. 914, 

 p. 4, fig- 1) ■ — A brief description is given of the cluster cups caused by JEcidium 

 punctatum on anemones. The diseased plants are readily recognized by the pale 

 curled leaves supported on long leaf stalks, which are much more erect and longer 

 than in healthy plants. A plant once affected should be destroyed, as the mycelium 

 passes into all parts, and after becoming infected the plants seldom or never bloom. 



Cucumber and melon mold, M. C. Cooke (Gard. Chron., 3. ser., 36 (1904), No. 

 923, pp. 17.', 173).— The author describes the condition of some cucumber leaves 

 which were affected with circular spots that could not be distinguished from those 

 caused by the fungus Cercospora melonis. It was claimed that the fungus had been 

 killed by heavily fertilizing the plants with potash fertilizers. When examined the 

 leaves of the cucumber presented the characteristic spots of the well-known cucumber 

 mold, but no trace of the fungus could be found. 



The entire absence of mycelium and other portions of the fungus led the author to 

 believe that possibly the development of the fungus was arrested by the use of the 

 fertilizer, as claimed. As having a bearing on the treatment of other diseases, the 

 author records this fact, and believes the subject worthy of further investigation. 



Bitter rot of apples, M. C. Cooke ( Gard. Chron., 3. ser., 36 (1904), No. 928, pp. 

 249-251, figs. 5). — Notes are given of the bitter rot of apples, due to Glatosporium fruc- 

 tigenum, and the various phases of the disease are described, the author drawing 

 extensively on Bureau of Plant Industry Bulletin 44 (E. S. R., 15, p. 270). 



Collar rot or gum disease, C. Fuller (Natal Agr. Jour, and Min. Rec, 7 (1904), 

 No. 11, pp. 1041-1050). — In a previous publication (E. S. R., 15, p. 52) the author 



