1919] DISEASES OF PLANTS. 349 



Citrus canker eradication, I. 15. P. Kv.ws (So. African Fruit Grower, k 

 (1918), No. 10, p. 192).— The author states that, at the end of March, 1918, 

 citrus canker had been found only in the Cap*- arid Transvaal Provinces, which 

 showed three and two outbreaks, respectively. 



Buried coconut trunks and root diseases of rubber, F. W. South (Agr. 

 Bill. Fed. Malay States, 6 (1918), No. 6, p. 269).— An account Is given of the de- 

 velopment of disease in rubber trees between the rows of which coconut tr< 

 had been buried some three years before. The rubber trees were affected with 

 brown root disease (Hymenochcete noxia) and wet rot (Porta hypolaterita) 

 working together or separately, the last named having attacked much of the 

 buried wood. The disease was traceable down the roots of the rubber trees to 

 the coconut logs. When the attack had not reached the collar, removal of i la- 

 diseased roots saved the rubber trees. 



The spraying of tea in northeast India, A. C. Tunstaix (Agr. Jour. India, 

 Indian Sci. Cong. No., 1918, pp. 78-80). — This is a general account of the con- 

 ditions for the growing of the tea, with discussions of tea diseases and their 

 control, including both devices and organization. 



A number of ready-made preparations have been tested, and lime-sulphur 

 solutions appear to be the most satisfactory on the whole, either as Insecticides 

 or fungicides. 



Disease in forest trees caused by the larger fungi, E. Cheel and J. B. 

 Cleland (Forestry Com. N. S. Wales Bui. 12 (1918), pp. 12, pis. 20).— Deserip- 

 lions are given of injury to timber trees caused by a number of species of 

 Armillaria, Pholiota, Polyporus, Polystictus, Fomes, Hexagona, and Trametes. 



Notes on forest tree rusts, J. R. Weir and E. E. Htjbebt {Phytopathology, 8 

 (1918), No. 3, pp. 114-118). — Notes are given on a number of forest tree rusts, 

 In which the different stages of the life history are described and also the 

 presence of new hosts indicated. 



Resistance in the American chestnut to the bark disease, A. H. Graves 

 (Science, n. ser., 1,8 (1918). No. 1252, pp. 652, 653). — During an investigation on 

 the American chestnut, looking toward immunity or resistance to the bark dis- 

 ease, the author discovered a considerable number of resistant trees in the 

 vicinity of New York City. The evidence regarding the resistant quality of 

 these trees is based on inoculation tests, the occurrence of the trees in a neigh- 

 borhood long subject to the disease, the apparently long period the disease has 

 been present in the trees as indicated by healed cankers and thrifty branches 

 with diseased bases, peculiarities of the bark, and the natural grouping of the 

 trees in well-defined areas which seem to point to genetic variation. A large 

 number of nuts has been gathered from some of the trees and planted for 

 further observation. If the resulting seedlings should substantiate the inference 

 that the disease resistance is a heritable character, it is believed that by in- 

 breeding and by crossbreeding with the resistant oriental species It will be pos- 

 sible to develop a resistant, if not an immune, strain ..f timber tree for the re- 

 forestation of the devastated chestnut woodlands of the United States. 



Some observations on the development of Peridermiura cerebrum, B. O. 

 Dodge and J. F. Adams (Mem. Torrcy Hot. Club. 11 (1918), pp. 253 !'>1. pis. 3, 

 figs. 3). — This is a study of P. cerebrum on Pinus rigida and P. riryiniana, 

 presenting points of interest which are discussed. 



Infections have been accomplished with ]'< ridenninm cerebrum on QueroUB 

 ilivifolia, Q. marilandica, and Q. hctcropluill'i. 



Advance rot and latent defects in aeroplane timber, J. S. Boyce (Aerial 

 Age, 7 (1918), No. Ik- pp. 67k. 675. 691).— Popular descriptions are given of a 

 number of the rots attacking the Sitka spruce, Douglas fir, and other timbers 

 used iu aeroplane construction. 



