DISEASES OF PLANTS. 49 



were produced and the orKauisin was re-secured. Attempts to inoculate apples 

 failed, the cultun>s reniahunjj; sterile. 



The author undertook to locate the organism in the trees during the winter, 

 making cultures from the inner bark of twigs, but the cultures remained 

 sterile. Cultures taken from other parts seemed to indicate that the organism 

 remains over winter in the inner bark of the larger branches, but dies in the 

 smaller ones. 



Bacterial blight of apple, pear, and quince trees, D. H. Jones {Ontario 

 Dept. Agr. Bui. 176, pp. 67/, pi. 1, figs. 58). — The author describes the bacterial 

 blight of apple, pear, and quince trees, due to BaciUus ami/lovoriis, giving 

 accounts of the occurrence of the organism in the fruit, leaves, twigs, and 

 trunk of the trees. The spread of the disease by means of various insects, 

 pruning utensils, etc., is described, and suggestions are given for its control. 



A bililiography is appended. 



A disease of cacao fruits, F. Gueguen (Compt. Rend. Soc. Biol. [Paris], OS 

 (1910), No. 5, pp. 221, 222). — A description is given of a disease of cacao fruits 

 that is attributed to one of the molds which is apparently identical with or 

 closely related to Acrostalagmus vilmorinU. This fungus has previously been 

 found on the China aster (E. S. R., IS, p. 749). 



Most of the cacao pods attacked had been perforated by a scolytid beetle, 

 and it is thought that probably the fungus gained entrance in this way, al- 

 though some specimens were found in which there did not seem to be any 

 external opening. In this case the author believes that the penetration was 

 through the conductive tissue of the style, the infection having been made when 

 the plant was in bloom. 



Diseases of coconuts, L. A. Waxes {Jour. Jamaica Agr. Soc, 13 {1909), No. 

 /,?, pp. .'i3't-Jf36). — Three distinct troubles of young coconuts (bud rot, root 

 disease, and borers) are often present in coconut plantations and it is hard to 

 distinguish one from another. 



In bud rot the trunk of the tree is not affected and does not show signs of 

 sickness until the tree is dead. Root rot is recognizable by the exudation of a 

 bright yellow gum beginning around the crown of the trunk at the ground level. 

 All diseased bark and wood and adhering roots should be cut out as soon as 

 ob.served, and the cut surface well cauterized with fire and then coated with a 

 heavy application of tar. The borer may be recognized by a brown, watery 

 exudation and can be destroyed by tarring the trunk. 



The immunity of the Japanese chestnut to the black canker, A. Pkttnet 

 (Bui. ,s'w. Nat. Agr. France, (>!) {1909), No. 10, pp. 926-931; Rev. Vit., 33 

 {1910), No. 838, pp. 21, 22). — The culture of chestnuts is seriously threatened 

 by this disease in Portugal, Spain, and Italy, while in France it has destroyed 

 over 2r),(K)0 acres of chestnut gi'oves. 



Experiments have been conducted for several years in various portions of 

 France with the American chestnut {Castanra deiitata) and the J-ipanese 

 ch(>stnut {C. erenata) to ascertain their relative inununity to this disease. The 

 Japanese trees after periods of 5 to 7 years' growth in infected regions proved 

 immune, but both native and American chestnuts in the same groves died from 

 attacks of the fungus. 



The systematic position of the oak mildews, F. W. Neger (Naturir. Ztschr. 

 Forst u. Landw., 7 {1909), No. 2, pp. U.',-119, figs. 3).— In a study of the 

 OTdium forms of Phyllactinia and Microsphiera to determine if possible the 

 identity of the oak mildew so prevalent in Europe in IDO.S, it was found that 

 neither the conidia nor the haustoria of Phyllactinia are similar to those of the 

 oak mildew. The author therefore concludes that the oak mildew is not a 

 Phyllactinia but is probably the American mildew {Micros phwr a cxtcnsa). 



