DISEASES OF PLANTS. 363 



oiiidii l)ulbs, young leafstalks of ivlery, loaves and flower stalks of hyacinth, cab- 

 bage, and green tomatoes -were all more <ir less snccessfnlly inoculated, the charac- 

 teristics of the disease being produced in a comparatively short time. In a number 

 of instances it was found nei-essary to keep the inoculation material moist, as the 

 wilting or drying of the material checked the development of the disease. The 

 experiments in the inoculation of oranges, bananas, apples, pears, potatoes, sweet 

 potatoes, and garden beets gave negative results; and similar results were obtained 

 where the roots and leaves of young plants of carrot and parsnip and the stems and 

 petioles of tomato were inoculated The methods of inoculation and the character- 

 istics of the destruction by the organism are described. The cause of the disease is 

 said to be a new species of liacillus, to which the name Bacillus carotovorus is given. 

 In old cultures the bacillus exhibits rounded ends, but in young cultures frequently 

 long filaments are produced. In size the individual organism varies from 1.5 to 5/i 

 in length, and from 0.7 to 0.8// in diameter. It stains fairly readily, and so far as 

 known does not produce capsules. Physiological action of the organism in various 

 culture media is described at considerable length. 



As possible means for the prevention of this disease, the author recommends rota- 

 tion of crops in which the soil which has become contaminated may be kept for some 

 years in cereals, grass, potatoes, beans, or similar crops. In no case should manure 

 from animals fed diseased carrots or should compost from garden refuse be applied 

 to soil if the presence of the disease is suspected. When roots are to be stored they 

 should be thoroughly dried, and as sunlight exerts a very destructive influence upon 

 the bacteria in cultures, it is believed that spreading the roots for 2 hours in bright 

 sunlight would destroy the organisms jiresent in the roots. In stored roots the dis- 

 ease may be prevented ])y keeping the root cellar at a uniformly low temperature. 



Cucumber diseases, H. Garmax {Kentucky Sta. Bui. 91, pp. 50-36, fig. 1). — Descrip- 

 tive notes and directions for the prevention are given in the following diseases of 

 cucumbers, cantaloupe, and other cucurbitaceous plants: Cucumber mildew, melon 

 and cucumber anthracnose, cucumber-leaf spot, cucumber spot, cantaloupe-leaf spot, 

 damping off, timber rot and leaf glaze, cucumber wilt, watermelon wilt, and cucum- 

 V)er dodder. 



Aster diseases; nematode worms; and cucumber mildew, G. E. Stone and 

 R. E. Smith {Massachusetts Sta. Ept. 1900, pp. 71-7S). — The authors report extensive 

 experiments with China asters, in which experiments were conducted with some 

 15,000 plants to test the effect of fertilizers, varieties, time of planting, etc., on dis- 

 eases. The China aster is said to be affected by a number of serious troubles, the 

 most prominent of which appears not to be due to any organism, but rather the 

 result of a disturbance in the assimilative functions of the plant. The conditions 

 which bring about this disturbance, so far as their experiments show, are not yet 

 understood. 



A peculiar disease of potted cuttings of perennial jihlox was noticed during the 

 winter which proved to be caused by a species of nematodes. This nematode, unlike 

 the ones occurring on the roots of many i>lants, attacks the stem of the plant, causing 

 an abnoiTnal enlargement, while the leaves are stunted or in some cases reduced to 

 mere rudiments, and the plant generally dies. The species appears to be undescribed, 

 and this is the only reported occurrence, so far as the authors know, in the State. 



During the past year the presence of the cucumber mildew {Plasmopara cuhensis) 

 is reported as occurring on greenhouse cucumbers in 2 distinct and remote loc^alities. 

 This appears to be the first time it has been observed in Massachusetts since 1889 

 (E. S. R., 3, p. 160). 



Notes on plant diseases, W. Lociiiieao {Ontario Agr. Col. and ExpA. Farm Rpt. 

 1900, pp. 15, 10, 18-^' I, Jigs. ,3). — A brief description is given of the celery blight 

 {Cercospora apii). For its prevention the author rect)nunends spraying the plants at 

 intervals of 2 weeks with ammoniacal cojiper carbonate solution. The occurrence 



