DISEASES OF PLANTS. 853 



brown and fall, also to attack the branches, causing them to die back, and 

 finally destroying the whole plant. This malady is declared to be totally inde- 

 pendent of that said to be caused in the same neighborhood by Peridennium 

 strohi though the two may exist simultaneously and be confused in consequence. 



Recent observations on some diseases of white pine and yew, G. Fron {Bill. 

 Trlmcst. Soc. MycoL France, 27 (1911), No. /,, pp. J,16--'iSl, ftf/s. 2).— In con- 

 tinuation of work noted above and previously (E. S. R., 20, p. 549) the author 

 considers further the disease due to Lophodcnnium hrachijsporurn, here asserted 

 to be confined rigorously to young plants of Pimis strohus. A more detailed 

 description of the parasitic fungus is given, followed by a brief discussion and 

 description of the development of Gloeosporium taxicolum, said to be sapro- 

 phytic on yew (Taxus Mccata), together with notes on the effects of the 

 disease caused by its presence and progress. 



A black knot disease of Dianthera americana, I. M. Lewis {Mycologm, .'/ 

 (1912), No. 2, pp. 66-71, pis. //). — A description is given of a disease of the 

 water willow (-D. americana) , in which the aerial portions of the plant exhibit 

 numerous hypertrophied areas m the internodes. The general appearance of 

 the disease is somewhat like that of the black knot due to Plowriglitia vi-orbosa. 

 It is believed to be due to the fungus Bagniesiella dianthcrw n. sp., a technical 

 description of which is given. 



A disease of rubber during' curing', H. Lonay (Agron. Trop., 3 (1911), No. 

 6-7, 1, p. 90). — According to the author, there are frequently noted in the Straits 

 Settlements on Para rubber crape, during its drying, blood-red spots sometimes 

 attaining the size of an inch in diameter. These are due to the chromogenic 

 bacterium Micrococcus prodigiosus. They usually appear from the twelfth to 

 the fourteenth day of drying, develop rapidly, but disappear on the complete 

 drying of the rubber. After a period of (i weeks or more their presence can not 

 be detected, and apparently their occurrence has not in any way injured the 

 quality of the rubber. It is thought that they live orf the starch which is con- 

 tained in the rubber and disappear upon its consumption. 



A new wood-penetrating alga, G. T. Moore (Abs. in Science, n. ser., 35 

 (1912), No. S91, p. 153). — A brief note is given on the penetration of the cells 

 of a yellow-pine board, which had been submerged in the aquarium for several 

 years, by an alga which is believed to be allied with the Cladophoracete. 



Copper fungicides, S. TJ. Pickebing (Jour. Agr. Sci., Jf (1912), No. 3, pp. 

 273-281). — Previous investigations reported by the author (E. S. R., 28, p. 50) 

 have led to the conclusion that the efficacy of such substances as fungicides 

 depends on the proportion of copper in them which is rendered soluble by the 

 carbon dioxid of the air, and that if a deficiency of lime is used one of the 

 lower basic sulphates of copper is obtained, from which carbon dioxid liberates 

 a much larger proportion of copper than it does from the more highly basic 

 sulphates present in ordinary Bordeaux mixture. Experiments with the so- 

 called Woburn Bordeaux were believed to show that from IS to 20 times more 

 copper was rendered soluble than that. from ordinary Bordeaux mixture, and 

 it was recommended that the proportion of Woburn Bordeaux should not be 

 reduced below ts of that of ordinary Bordeaux mixture. Recent experiments 

 have indicated that ordinary Bordeaux mixture is equivalent in its fungicidal 

 action to Woburn Bordeaux containing only about i as much copper. 



The principal portion of this paper is taken up with a discussion of the theory 

 of Barker and Gimingham on the solution of copper by fungi (B. S. R., 25, 

 p. 458). 



- The use of copper oxychlorid as a fungicide, E. Chuaed (Jour. Agr. Prat., 

 n. ser., 22 (1911), No. 38, i)p. 37//, 375).— The question of the possible injurious 

 effect of copper adhering to grapes that had been sprayed with copper oxychlorid 



