DISEASES OP PLANTS. 159 



overcrowded nursery seedlings by mites are noted, and dusting witli flowers of 

 sulphur is recorumeuded as a remedy. 



A new leaf disease of Hevea from. Surinam, ]Mevr. A. E. Van Hall-de 

 JoNGE (Dept. Landb. Sari name Bui. 2-'i, pp. 6, pis. 2). — A description is given of 

 a new leaf spot of Para rubber which appeared in 1908 in the nursery at the 

 Botanic Gardens. 



The fungus attacks only young leaves, forming spots which spread in con- 

 centric circles on the underside of the leaves. The disease is very infectious, 

 and has spx-ead rapidly in the nursery because of the overcrowded condition of 

 the seedlings, although trees in favorable circumstances are probably little 

 susceptible to it. 



Fungus galls on the roots of Kickxia elastica, F. C. von Faber {Ann. 

 Mycol., S (1910), No. J/, pp. Ji-'j9-.'i51, fig. 1). — A description is given of the char- 

 acteristics (structural, etc.) of certain galls found on the roots of Kickxia 

 seedlings. 



The diseased plants are easily recognized by their small, yellowish, drooping 

 leaves, this being due to a poorly developed root system iu which the smaller 

 rootlets are often devoid of root hairs, and terminate in gall-like thickenings. 

 a microscopical examination showed numerous hyphae of some unl^nown fungus 

 present in the diseased tissue, and these were supposed to be the cause of the 

 hypertrophied condition. 



The sudden death of old twigs on the horse chestnut, R. Latibert (Aiis 

 der Natur, 5 (1909), No. 16, pp. 7/99-501 ) .—Attention is called to the sudden 

 wilting and final death of old twigs of the horse chestnut, due, it is claimed, to 

 attacks of the fungus (Nectria cinnabarina) which enters through wounds 

 produced by stoning the trees, and by live stock, wind, etc. 



The formation of galls on Juniperus cominunis, G. Severini (Ann. Bot. 

 [Rome], 8 (1910), No. 2, pp. 253-262, pi. i).— In a study of the structure and 

 causes of the galls formed on the twigs and branches of J. communis, it was 

 found that the excrescences were always associated with pre-existing lesions 

 in the tissues, especially with those corresponding to the leaf traces, and were 

 produced principally by the activity of the phellogen, and, secondarily, by the 

 cambium. 



The mycelium of a Ceratostoma (probably C. jmdperimim) was constantly 

 present in the affected tissues, even in the very young stages, and had its seat 

 exclusively in the periderm tissues, especially in the phelloderm, where its vege- 

 tative stages were developed after a special manner. 



The disease was reproduced by inoculating healthy twigs with the vegetative 

 mycelium of the fungus. The presence of colonies of Schizomycetes iu the 

 affected tissues was not observed. 



The leaf blight of the American mistletoe (Phoradendron flavescens), 

 F. A. Wolf (Mycologia, 2 (1910), No. 5, pp. 2.il-2-'i-'i, pi. i).— A description is 

 given of a disease of the mistletoe in Texas, which manifests itself by chlorosis 

 of a part or the whole of the leaf. The affected foliage becomes dark, dies, and 

 finally falls off. 



It is caused by a fungus (Macrophoma plioradendrl n. sp.), a technical 

 description of which is given. 



Observations on the new twig and bud disease of lilacs, G. Lijstner (Bcr. 

 K. Lehranst. Wcin, Ohst u. Gartetibau Gcisenheim, 1909, pp. 131-133) .—The 

 occurrence of this new lilac disease (Phytophthora syrin(/(p). previously noted 

 from Hamburg and vicinity (E. S. R., 22, p. 749), is reported on lilacs from a 

 Rhenish province and on plants in several gardens in Frankfurt. 



Chrysanthemum Alice M. Love and the rust fungus (Gard. Chron., 3. ser., 

 J,8 (1910), No. 1239, p. 23-} ) .—Attention is called to the complete immunity of 



