DISEASES OF PLANTS. 351 



Scald of tobacco plants by Paris green, L. P. de Bussy and P. A. Diet?; 

 (Medcd. Deli-Proefstat. Medan, 9 (1915), No. 1, pp. 15-25).— It is stated that 

 the degree of injury due to leaf scald as the result of using Paris green on 

 tobacco plants in Deli appears to increase somewhat in proportion to the 

 amount of free arsenious acid present therein. Other factors mentioned are 

 mechanical injury to the tender moist leaves, and excessive quantity or lack 

 of uniformity of the arsenical sprays. It is suggested that careful prelimi- 

 nary tests be made with gradually increasing percentages of the preparation. 



The bacterial bloom and twig blig'ht of fruit trees, A. Ostehwaldek 

 (Landw. Jahrb. Schtvei;z, 29 (1915), No. 1, pp. 29, 30).— It is stated that in 1912 

 a variety of pear was severely injured by a bacterial invasion of the blooms, 

 extending to the twigs, which also quickly withered and died, the effects re- 

 sembling somewhat those due to Monilia fructigena. It is thought that the 

 disease may be similar to the pear blight in America caused by Bacillus amylo- 

 vorus, but complete identification of the organism has not yet been found 

 possible. 



Studies of Monilia blight of fruit trees, G. B. Posey (Abs. in Phytopathol- 

 ogy, 5 (1915), No. 5, p. 294; Science, n. ser., 42 (1915), No. 1086, p. 583).— The 

 author reports the isolation from blighted twigs of apricot, prune, and pear 

 of a species of Monilia apparently unlike, in cultural characters, the common 

 brown-rot fungus of the stone fruits due to Sclerotinia cinerea, which is 

 abundant in Oregon. An investigation of this blight-producing Monilia has 

 been undertaken, and more than 50 strains have been isolated and comparative 

 studies made with S. cinerea from different parts of this country and with 

 S. fructigena from England. The culture studies and inoculations indicate 

 that the organism in question is apparently an unrecognized species of Monilia 

 entirely distinct from »?. cinerea and S. fructigena. 



The investigations thus far show that this fungus is apparently common in 

 the Northwest, where it has been found on blighted blossoms, spurs, and twigs, 

 und on mummied fruits of pear, quince, apricot, peach, prune, plum and 

 cherry. It usually starts in the spring as blossom blight and works back into 

 the spurs and branches, where the progress of the fungus is checked as the 

 season advances. No ascospore stage of the fungus under investigation has 

 been found, although apothecia of the common S. cinerea were collected on 

 various mummied fruits. 



Bacterial canker of cherry and filbert disease, H. P. Bakss (Ahs. in Phyto- 

 paihology, 5 (1915), No. 5, p. 292; Science, n. ser., 42 (1915), No. 1086, p. 581).— 

 The author calls attention to the identity of the cause of bud blight and body 

 canker of cherry trees, an account of which has been previously given (E. S. R., 

 S2, p. 644), and to the bacterial disease of filbert which has already been 

 described (E. S. R., 32, p. G47). 



The utilization of certain pentoses and compounds of pentoses by Glom- 

 erella cingulata, L. A. Hawkins (Amer. Jour. Bot., 2 (1915), No. 8, pp. 375-388; 

 abs. in Phytopathology, 5 (1915), No. 5, p. 294,' Science, n. ser., 42 (1915), No. 

 1086, p. 583). — A report is given of experiments made to determine the effect of 

 the apple bitter-rot fungus upon the pentose-containing compounds of the apple 

 fruit, the relative value of certain pentoses and compounds of pentoses as 

 sources of carbon for this fungus, and the effect of an aqueous extract of the 

 fungus mycelium upon xylan. 



It was found that the fungus increased the alcohol-soluble pentosan content of 

 the apple fruit, but decreased the total pentosan content. It readily utilized 

 either xylose, arabinose, xylan, or arabin as sources of carbon. The two pen- 

 toses were more favorable sources of carbon than glucose. Aqueous extracts 

 of the fungus mycelium when allowed to act on xylan produced xylose, and 



