ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 689 



it grows only in the stalk, causing an abnormal branch development with 

 a dwarfing of the leaves. The fungus produces only teleutospores ; the 

 mycelium is very abundant in the pith, and passes out to the cortex 

 chiefly at the leaf bases where the sori are usually found, though they 

 also extend up the internodes. The intercellular spores are filled with 

 hyphas, and haustoria penetrate the cells. The hyphas were found to 

 have penetrated the youngest branches. Magnus made a careful search 

 for mycoplasma, but was unable to find any evidence of its presence in 

 the tissues. 



Infection of Cereals by Smut.* — L. Hecke has been testing the 

 effects of copper sulphate treatment of seeds to destroy any spores of 

 Ustilago adhering to them. He has come to the conclusion that the 

 fungus infects the seed before it is ripe, and is thus contained within it 

 when it is sown the following year. He experimented with corn that 

 was artificially infected when flowering, and of which some of the seeds 

 ripened and seemed healthy. These seeds protected from further infec- 

 tion were sown, and produced smutted heads. 



Copulation of Conidia in Ustilago Tragopogi-pratensis.t — H, 

 Federley has observed the copulation of the conidia of this fungus and 

 the fusion of the nuclei. He noted some remarkable differences in 

 material gathered at different seasons. In autumn material the spores 

 would not germinate in any nutritive solution : they germinated only in 

 pure water. Fusion took place between the conidia, and long hyphre were 

 formed. The spores from fungi collected during the summer germinated 

 either in water or in nutritive media ; the promycelium gave rise to 

 numerous conidia, which multiplied by budding, but copulation was. 

 never observed, and the addition or exhaustion of nutrition had no effect 

 in inducing fusion. 



North American Polyporaceas.J — W. A. Mnrrill continues his work 

 on this group. He revises the two genera Hapctlopilus and Pycnoporus ; 

 the former to contain forms with an " anoderm surface and fleshy-tough 

 context " ; the latter for the two species Polyporus cinnabarinus and 

 P. sanguineus. His new genera are Abortiporus, Gyclomycetella, Cyclo- 

 porus, Globiformes, Nigroformes and Poronidulus, all of them so far 

 monotypic, and founded on various speeies of Polyporus. 



Dry-rot. § — B. Malenkovie finds that the infection of dry-rot is due 

 to the spores of the fungus rather than to the mycelium. He thinks 

 that calcium carbonate, which is found on wood near the walls, offers 

 a favourable medium for the growth of the fungus. He recommends 

 light and air as the best means of preventing the growth of Meridius. 

 In another paper j| the same author gives results of his work on the ger- 



* Zeitschr. landw. Versuchsw. Oesterr., 1904. See also Ann. Mycol., ii. (1904) 

 pp. 376-7. 



t Finska. Vetensk.-soo. Forh., xlvi. (1903-4) No. 2. See also Bot. Zeit., lxii.(1904) 

 pp. 171-2. 



X Bull. Torrey Bot. Club, xxxi. (1904) pp. 415-28. 



§ Centralbl. Ges. Forstw., xxxix. (1903) pp. 281-9G. See also Centralbl. Bakt., 

 xii. (1904) pp. 511-2. 



|] Naturw. Zeitscbr. Land und Forshw., ii. (1904) pp. 100-9, 160-3. See also 

 Centralbl. Bakt.. xii. (1904) pp. 512-3. 



