1918.] DISEASES OF PLANTS. 647 



crossings made four years previously which have proved resistant to rust, 

 and other matters, the author states tliat it has not been necessary to spray 

 coffee in the botanic garden since 1914 for the coffee leaf disease (Hemileia 

 vastatrix). This disease is easily brought under control by pruning and by 

 one or two applications of any dilute fungicide, after which one spraying each 

 year is sufficient if weeding and pruning are properly attended to. The quarter 

 strength mixtures are not so effective against this fungus on coffee at lower alti- 

 tudes (such as that at the Government Farm, Kibos). This is probably due to 

 the greater warmth and moisture of the climate. 



Citrus (lime, lemon, and orange) trees shoAved marked improvement after 

 being sprayed with Bordeaux mixture and lime-sulphur after the long rains of 

 1915. It is also recommended that the latter treatment be continued before the 

 short rains in November. 



[Plant diseases, Bombay Presidency], W. Burns (Aim. Rpt. Dept. Agr. 

 Bombay, 1915-16, p. 69). — The use of copper sulphate on sugar cane sets, in 

 addition to being harmful to the plants, proves to be ineffective in preventing 

 smut, which may be transmitted through aerial infection also. Red rot is 

 exaggerated by an excess of water. The band disease of betel nut palms, said 

 to be new here and to result in sterility, is under investigation, no fungus or 

 insect having yet been identified as the cause of the trouble. A gi-eat increase 

 is noted in the number of these trees sprayed for the koleroga disease of the 

 betel nut palm. 



[The effect of defoliation, of g'ases, and of fung'i on plants], R. Eweet {Ber. 

 K. Lehranst. Obst u. Gartenbau Proskau, 1914, PP- 156-163; Landw. Jahrb., 48 

 (1915), Ergdnzungsb.). — Removal of blooms from an apple tree 45 years old 

 having been followed the next spring by the production of blooms, the same 

 treatment was tried on a tree 22 years old, with inconclusive results, neither 

 this tree nor its control producing more than a few blooms. Some trees which 

 lost their blooms through attacks of insects are said to have produced a good 

 crop the next year. 



Anthracene produced an effect on bush pea and Polygonum sieboUli similar to 

 that given by coal-tar vapors. 



Leaf cast of apple appeared this year to be Independent of the presence of 

 Fusicladium. 



A study reported by Killian on the life history of Yenturia incequalis is 

 briefiy discussed, as is also one by Pietsch on Trichoseptoria fructigena, the 

 cause of a rot in quinces and apples. 



Normal parasitism and microbiose, V. Galippe {Campt. Rend. Acad. Set. 

 [Parish, 165 (1911), No. 4, pp. 162-164). — The author has given attention to 

 the results of traumatism considered as favoring the development, particularly 

 in fruits but also in animal organisms, of various kinds of the intracellular 

 microscopic fungi and (rarely) yeasts which are normal to them. These have 

 been called microzyms, and, it is claimed, may be caused in different ways (some 

 of which are indicated) to enter upon a developmental phase at the expense of 

 the cells. Microbiose is the name applied to the corresponding intracellular 

 organisms in animals. 



Norpaal parasitism has been studied as developed in apples by the application 

 of pressure or of cold. Normal parasitism and microbiose appear to constitute 

 a general feature of living cells, so that traumatism may develop, in addition, 

 a quasiparasitism without any infection from without or in addition to the 

 latter infection, which may really be a secondary feature of the trouble. This 

 is regarded as having significance in case of wounds from projectiles, which, 

 though absolutely aseptic, may determine an infection by the normal intra- 

 cellular organisms. 



