DISEASES OF PLANTS. 463 



/). S21, fir/s. 7). — Results of experiincnts ))y J. W. Touincy of tho Arizoiui Station 

 p. 458)."' 



The scab disease of apples, pears, etc., and its treatment, Weiss {Prakl. Bl. 

 Pflanzenschutz, 1900, No. 2, pp. 9-11). 



Apple mildew, P. Magnus {Centbl. Bakt. u. Par., 2. AbL, 6 {1900), No. 8, pp. 253-255, 

 figs. 2). — A discussion as to the specific relationship of the fungus causing apple mildew. 

 The author doubts the occurrence of SpJueruiheca rnali on apple trees. As a preventive 

 the author speaks very highly of sulphur. 



Means of protection from the so-called scab of pomaceous fruits, Fkank 

 {Sep. Arh. K. (inoinilhe'dmmte, Biol. Aht., 1900, pp. 4, fig- ^) ■ 



Canker in fruit trees and its treatment {Garden, 57 {1900),, No. 1478, pp. 197, 

 198). — A translatic m of an article treating of the attack of Nedriu d'dissima with sugges- 

 tions for its prevention. 



Leaf curl in peaches and nectarines ( Garden, 57 { 1900) , No. 1479, p. 224, figs. 

 2). — Notes on Exoascus deformans and suggestions for its prevention. 



The shot-hole fungus {Garden, 57 {1900), No. 1480, p. 345, figs. <?).— Figures and 

 describes the shot-hole fungus Cercospora circuincisru. 



The biology and practical suggestions for combating hexenbesens in cherry- 

 trees, C. Freiherr vox TuBEUF {Arb. K. Gesundheitsainte, Biol. Abt. Leaflet 4, 1900, 

 pp. 4, figs. 4). 



Witches brooms of Pinus sylvestris, A. W. Borthwick ( Tran.s. and Proc. Bot. 

 Soc. Edinburgh, 21 {1900), pp. 196, 197). 



Some citrus troubles, H. H. Hume {Florida Sta. Bid. 53, pip. 147-173, pils. 6, figs. 

 5). — The author describes foot rot, scab, dieback, sooty mold, !)light, melano.se, and 

 leaf spot — diseases of citrus fruits — and the injuries caused by the presence of lichens 

 and moss upon the trees. Most of these diseases have been previously described in 

 U. S. Dept. Agr., Division of Vegetable Physiology and Pathology Bui. 8 (E. S. R., 

 8, p. 58 ) , and the recommendations there given for the prevention of the diseases 

 are repeated. The leaf spot disease is described as being slightly injurious to orange 

 trees in some parts of the State. Large, somewhat circular, yellowish spots are 

 noticed upon the leaves which are attributed to Colletrotrichum glaosporioides. Spray- 

 ing trees with ammoniacal solutions or Bordeaux mixture is recommended. The 

 injury done by lichens and moss ( Tillandsia usneoide.^) is mentioned and the destruc- 

 tion of the lichens by spraying with strong Bordeaux mixture is recommended, 

 while the moss may be removed by pulling it from the trees. 



Collar rot or mal-di-gomma of citrus trees {Agr. Gaz. Neiv SoiUh TFofes, 11 

 {1900) , No. 8, pp. 660-668). — This disease, which is also commonly known as foot rot, is 

 due to Fusariurn limonis. The symptoms of the disease, conditions favoring its spread, 

 means for its jirevention, and history of the disease in Australia are given. The treat- 

 ments recommended in U. S. Dept. Agr., Division of Vegetable Physiology and 

 Pathology Bui. 8 (E. S. R., 8, p. 58), are suggested as means for prevention. 



Chlorosis of fruit trees, C. Bouillot {Semaine Hart., 1900, pp. 23, 35, 36, 59, 60, 

 95). 



Chlorosis of the vine, G. Curtel {Compt. Rend. Acad. Sci. Paris, 130 {1900), No. 

 16, pp. 1074-1076; (d>s. iti .Tour. Boy. Micros. Soc. [London], 1900, No. 4, pp. 488,489) .— 

 The physiological injuries inflicted by chlorosis of the grape have been investigated 

 and it is shown that there is an evident weakening of the respiratory activity, a 

 diminution in the proportion of gases exchanged, a diminution and final cessation 

 of assimilation, and a great weakening of the fmictions of transpiration. The appear- 

 ance of chlorosis and the lowering of the transpiratory function appear to be indis- 

 solubly connected. 



Notes upon grape mildew, B. D. Halsted {Asa Gray Bid., 8 {1900), No. 4, pp- 



