1918] DISEASES OF PLANTS. 855 



satisfactory and that the subject still requires further patient investigation 

 before the disease can be successfully combated. 



Spike disease of sandal, L. C. Coleman (Dept. Agi: Mysore, Mycol. Ser. Bui. 

 3 {1917), pp. IV+52, pis. 19, figs. 3).— A study of the so-called spike disease of 

 sandal continued for several years is described in considerable detail in a re- 

 port which is considered as clearing the way for further studies of this trouble, 

 which is said to cause large and increasing losses over a considerable portion of 

 southern India. 



While the disease was not referred to any unfavorable condition in soil, 

 climate, or association as regards its causation, it is thought that unfavorable 

 conditions increase its virulence and transmissibility. The trouble shows itself 

 in a profound disturbance of the ordinary functions, leading to a continuous 

 growth of leaves and twigs, a characteristic reduction in the size of the latter, 

 an accumulation of starch in the leaves and branches, and death of the haustoria 

 and root ends. It is communicable by grafting, and supposedly due to an ulti-a- 

 microscopical organism. Similar and similarly infectious diseases have been 

 noted on other trees in areas where sandal grows. It is claimed that the disease 

 may be spread by means of root connections, birds, or insects. 



The efEect of Roentgen and ultraviolet rays upon fungi, H. L. Tbumbuix 

 and J. W. HoTSON {Phytopathology, 7 {1917), No. 6, pp. 426-431, figs. 2).— It is 

 stated that the museum of the University of Washington, Seattle, which served 

 as a forestry building during the exposition conducted in 1909, was built of 

 logs of green Douglas fir and western hemlock. These logs are said to be 

 showing signs of decay resulting from an attack of Pomes pinicola. Experi- 

 ments have been conducted to combat the ravages of the fungus, principally by 

 impregnation of the wood with copper and other salts, but to avoid the dlRiculties 

 of such treatment experiments were also conducted with Roentgen and ultra- 

 violet rays to determine the possibility of destroying the fungi. Exposures were 

 made to both kinds of rays for varying periods of time. 



The results obtained do not indicate that the method employed would prove 

 suitable for the control of such wood-destroying fungi as F. pinicola. 



Some problems connected v/ith the treatment of fungus diseases by spray- 

 ing, E. S. Salmon and J. V. Eyee {Rpt. Brit. Assoc. Adv. Set., 86 {1916), pp. 

 488, ^89).— This is mainly a discussion of the different avenues of approach 

 ordinarily open to the solution of the various jiroblems that arise in connection 

 with economic diseases of plants, namely the fungus itself, the host, and the 

 nature of the fungicide. Another aspect of the problem is the effect of a sub- 

 stance to increase the fungicidal properties of another substance, as in the case 

 of parafiin in a spray fluid containing soluble sulphid, or of soap in liver of 

 sulphur. Still another aspect is the question of securing intimate contact of 

 the spray with the fungus by the addition of ingredients to lower the surface 

 tension of the si^ray fluid and the measurement of such lowering. 



The conduction of potassium cyanid in plants, J. A. Elliott {Phytopa- 

 thology, 7 {1917), No. 6, pp. 44S-4Jt8, figs. 2). — A report is given of experiments 

 conducted by the author with herbaceous and woody plants to determine the 

 path of conduction of potassium cyanid through the plants and the extent of 

 local and general injury. 



It was found that potassium cyanid is conducted in the vessels and diffuses 

 from them into the surrounding tissues, the diffusion being greatest when the 

 conduction is slowest. Injury to the plants is said to be local, corresponding 

 to the distribution of the potassium cyanid, except where the local injury 

 has a secondary injurious effect on other parts of the plants. Actively growing 

 tissues are most readily killed. In woody plants, injury is dependent on the 

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