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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



long, while others were entirely girdled. The small wounds were 

 usually about the upper angles of the roots, and in cases of completely 

 girdled trees all lateral roots in the girdle were dead and decorticated. 



Another orchard which was inspected was found to have old crown-rot 

 scars on more than six per cent, of the trees — areas of bare wood of 

 various size surrounded by about thirteen-year-old callus rolls. It is 

 .suggested that the injuries all originated the same winter, and that the 

 good soil enabled the trees to recover. 



Crown-rot has been attributed to parasitic organisms, to arsenical 

 poisoning, and to low temperatures. The author thinks there is little 

 doubt that it is due primarily to low temperatures, late maturity of 

 young wood being specially favourable to injury from this cause. 

 Though parasitic organisms have been found on affected parts there 

 is at present nothing to prove that they are other than wound parasites. 

 Much investigation remains to be done, and the result may be new 

 methods of orchard management which will increase the winter hardi- 

 ness of the trees. At the end of the bulletin is a list of publications 

 bearing upon this and kindred subjects. — A. P. 



Dendrobium Sanderae {Bot. Mag. tab. 8351). — Nat. ord. 

 Orchidaceae ; tribe Epidendreae. S.-E. Asia. Epiphyte; leaves 

 2 inches long; racemes 1 inch long, 3-4 flowered; flowers large, white, 

 with purple stripes on the disk and lateral lobes of the lip. — G. H. 



Dimorphotheca. By J. M. Duvernay (Le Jard. xxiv. 565, p. 264, 

 September 5, 1910; with coloured plate). — This article enumerates the 

 various species of Dimorphotheca, including the now well-known 

 Barberton Daisies, and gave directions for their cultivation. — F. A. W. 



Diseases of cultivated plants in West Indies, Fung-i causing-. 



By C. K. Bancroft (West Indian Bull. vol. xi. 3, p. 235; 1910).— 

 " . . . A brief descriptive account of those fungi which have from 

 time to time been reported to be injurious to cultivated crops in the 

 West Indies " supported by references to authorities on each fungus. 

 Appendices include : Diseases due to bacteria, diseases due to physio- 

 logical causes. There is also an index of host plants and of parasites. 



C. H. L. 



Diseases of Garden Crops and their Control. By N. J. 



Giddings {U.S.A. Exp. Stn., West Virginia, Bull. 123, May 

 1909). — Short notes on the commoner diseases of garden crops, as to 

 the appearance of infected plants, &c., and formulae for the simpler 

 remedies are given with directions how to apply them. The author 

 points out that some diseases, especially those due to bacteria may be 

 spread by beetles and other gnawing insects, and recommends taking 

 measures to keep them down both under glass and in the open. 



D. M. G. 



Disinfection of Imported Plants. By H. A. Ballou {West 

 Indian Bull. vol. x., 4, p. 349; 1910). — This paper contains sum- 



