DISEASES OP PLANTS. 251 



Attention is called to diseases of bananas in other regions, and while it is not 

 definitely claimed that they are identical, such seems to be the indication. 



The specific organism has not yet been fully identified, and further investi- 

 gations upon it are in progress. 



On the blackening' of the seeds of cacao, caused by an Acrostalagmus, 

 F. GuEGUEN {Bill. Trimest. Soc. Uycol. France, 26 (1910), No. 3, pp. 287-297, 

 pis. 2). — A disease of cacao beans is reported from the Island of St. Thomas, 

 in which the beans while still in the pods on the trees are covered by a black 

 growth of the hyphal threads of a fungus, Acrostalagmus vilmorinii thomensis 

 n. var., a technical description of which is given. 



It is claimed that the fungus is introduced into the pods through the punc- 

 tures of a wood-boring insect, Xyleborus pcrforans, and the preventive measure 

 recommended is the destruction of the beetles by the use of insecticide sprays. 



A new West Indian cacao pod disease, C. K. Bancroft {West Indian Bui., 

 11 {1910), No. 1, pp. 34, 35, pi. 1). — A description is given of Colletotrichum 

 cradwickii n. sp., a fungus recently observed on samples of diseased cacao pods 

 received from Jamaica. The parasitism of the fungus remains to be established. 



Report on the outbreak of blister blig'ht on tea in the Darjeeling' District 

 in 1908-9, W. McRae {Agr. Research Inst. Pusa [India], Bui. 18, 1910, pp. 19, 

 pis. 6). — This is a more extended discussion of the outbreak of blister blight 

 on tea, previously reported from another source (E. S. R., 23, p. 749), including 

 a more detailed description of the gross and microscopic characteristics of the 

 fungus, additional data as to damage done, and the probable source of introduc- 

 tion into this district. 



Damages caused by Lophodermium macrosporum, E. Mer (Bui. Soc. Nat. 

 Agr. France, 70 (1910), No. 7, pp. 652-660). — Attention is called to the damage 

 done by this leaf cast fungus, especially under certain environments, when the 

 trees may be completely defoliated ; this may occur in nurseries or in dense 

 thickets of young trees from 15 to 25 years of age. The remedies recommended 

 are the use of copper sprays, the spreading of nitrate of soda between the rows 

 of trees, and setting the plants farther apart in the nursery. 



A biological study of Sterigmatocystis quercina, A. Sartory (Bui. Trimest. 

 Soc. Mycol. France, 26 (1910), No. 3, pp. 349-357, fig. 1). — The results are given 

 of studies of the sclerotia, microscopic structure, and growth of the fungus on 

 liquid and solid media. It was found that S. quercina was able to grow on all 

 the usual media employed for bacteriological cultures, and formed sclerotia on 

 potatoes and carrots. 



A leaf parasite of Quercus ilex, H. T. GtJssow (Jour. Bot. [London], 46 

 (1908), No. 544, P- 123, figs. 4; ahs. in CentU. Bakt. [etc.], 2. AM., 27 (1910), 

 No. 22-25, p. 653). — A technical description is given of a new leaf-spot fungus, 

 Ascochyta qucrcus-ilicis n. sp., which forms irregular spots on the leaves of 

 this oak. 



A study on the black canker of the chestnut, V. Ducomet (Ann. Ecole Nat. 

 Agr. Rennes, 3 (1909), pp. 1-70, figs. 40). — After a brief review of the history 

 of the disease and of various fungi claimed by different investigators as its 

 cause, the author discusses with much detail the various mycorrhizal fungi 

 associated with the roots of the diseased chestnuts. 



As a result of these investigations it is claimed that the disease is due to 

 three different agencies, viz, (1) a mycorrhizal fungus which has become para- 

 sitic on the roots, (2) a filamentous chytridiaceous fungus introduced by the 

 mycelium of the parasitic mycorrhiza, and (3) bacteria in the mycorrhizal 

 regions of the roots, introduced either directly by the normal or parasitic 

 mycorrhizal mycelium, or by the mycelium of the chytridiaceous fungus. 



