ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 461 



Value of Spraying for Plant Diseases.* — It is only the more 

 delicate leaf diseases that can be combated by spraying methods, but the 

 most widely prevalent and deadly fungi rank in this category. W. 

 Kelhofer has a long series of experiments with different compositions for 

 spraying against Peronospora, and he finds that Bordeaux mixture with 

 an excess of lime is by far the best ; that it adhered better to the leaves 

 during rainfall, and that it had very damaging effects on the fungi. He 

 found also that the injury to the host-plant was reduced to a minimum. 



Disease of Firs.f — L. Mangin and P. Hariot had occasion to 

 examine leaves of firs that had died, taking on a reddish colour, and 

 easily noted in the midst of the green living leaves. They found on 

 these leaves four fungi : Rhizospluera Abietis g. et sp. n., one of the 

 Sphere psidese, distinguished by the form of the perithecium ; the spores 

 are simple and hyaline. Another new genus, Menoidea, one of the 

 Tuberculariaceffi, was also diagnosed ; the spores are lunulate-arcuate, 

 simple and hyaline. The other fungi were 3£acrophoma Abietis sp. n. 

 and Ci/tospora Pinastri. The writers came to no definite conclusion as 

 to the cause of the disease, though they are inclined to the belief that 

 RhizospJuera, as the most wide-spread, was probably the origin and cause 

 of the malady. All the new forms are illustrated in the text. 



Plant Diseases. — 0. AppelJ has experimented with Merulius 

 lachrymans to determine whether it ever grew as a parasite. He 

 infected seedlings of various trees with the mycelium, without any 

 result. 



E. de Wildeman§ has examined coffee-plants on the Congo, and finds 

 that the fungus diseases most to be feared there are Pellicular ia Koleroga 

 and Hemileia vastatrix. The latter is not wide-spread on the Congo. 

 A number of new fungi were found on coffee-plants, but their economic 

 significance is not known. 



E. S. Butler 11 gives an account of the fundus diseases of sugar-cane 



no ~ o 



in Bengal, treating them in order as stem diseases and leaf diseases. 

 One of the most serious diseases is caused by CoUetotric/ium, which 

 attacks the stem. The fungi are fully described, and advice given as to 

 treatment of the diseased canes. 



A beginning has been made in the study of plant diseases in the 

 Rocky Mountain region, and I. H. Pammellf gives an account of some 

 of those that occur most frequently. Peridermiimi is a most destructive 

 parasite of Conifers, three species of the genus being common in the 

 country. P. cerebrum causes malformations on Pinus Murrnyana, 

 P. elat ilium gives rise to witches'-brooms on species of Picea and Abies, 

 and P. abieiimmi produces birds'-nest distortions also on Abies. The 

 ravages due to Exoascus and Taphrina are described, and the mildews 

 of plum and cherry due to Erysiphe.v. The writer also includes an 



* Zeitschr. Pflanzenkr., xvii. (1907) pp. 1-12. 



t Bull. Soc. MycoI. France, xxiii. (1907) pp. 53- 68 (9 figs.). 



X Arb. Kais. Biol. Anst. Land. Forstw., v. (1906) pp. 204-6 (2 figs.). See also 

 Ann. Mycol., v. (1907) p. 105. 



§ Comptes Rendus, cxlii. (1906) p. 1093. See also Ann. IMycol. v. (1907) p. 107. 



II Mem. Dept. Agric. India, i. No. 3 (1906) pp. 1-50. See also Bot. Centralbl., 

 civ. (1907) p. 477. ^ Iowa Acad. Sci., 1905, pp. 89-114 (6 pis.). 



