ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 429 



bifoUa. Piiccinia Schroeteri collected from Narcissus radiflorus infected 

 successfully N. pseudonarcissus . Sydow had given all species of Allium 

 as hosts for Puccinia Allii, but Schneider found in several instances that 

 infection rarely took place. F. Porri on Allium Schcenoprasum was also 

 experimented with ; it did not grow well on other species of the genus. 



Eriksson * has again taken up the question of. the wintering of rust 

 spores and the spring infection of wheat. He comments on the finding 

 by Pritchard of rust mycelium in the grains which would naturally 

 develop with the seedling plant. Eriksson considers the discovery of 

 great interest, but deprecates giving too much importance to it as it in 

 no way explains how the rust lives through the winter on other wheats. 



E. J. Butler t describes two species of rusts, Phakopsora Vitis and 

 Chrysomyxa Vitis. The development of both were studied. The author 

 considers them economically important, though so far they have only 

 been found on wild vines. It has so often been found that parasites on 

 wild plants may also attack cultivated plants. 



jEcidium of Puccinia fusca4— A. F. Pavohni has made a cytological 

 study of this Uredine. From the mycelial hypha^ rise the vertical rows 

 of uninucleate cells, at first crowded and slender, then at the stage of 

 binucleation larger. There is almost no formation of intercalary cells ; 

 the cells are all equally fertile, and as adult cells are frequently uni- 

 nucleate this condition depends on their position in relation to neighbour- 

 ing cells. Fusion occurs by the dissolution of the membrane of those 

 cells that touch each other. No cells are binucleate until the stage when 

 the JBcidium Ijreaks through the epidermis of the host. And it is more 

 exact to call the basal cells of the secidium simply hyphre. The bi- 

 nucleate cells only appear after the vertical cell rows are formed. The 

 further stages of spore-formation are also described and the appearance 

 of the nuclei. 



Variations in the Promycelium of Coleo8porium.§ — J. R. Weir 

 describes a variation that may be merely an abnormality in Coleosporitim 

 puhaiillae. The normal promycelium arises from the division of the 

 teleutospore into a column of four cells, or basidia, each of which pro- 

 duces a sporidium. In the case observed the basidia were arranged in a 

 tetrad and occurred alongside of the usual type of promycelium. It was 

 formed most frequently at the inner edge of the sorus and germinated in 

 the usual way. 



Sexual Fusions in Flax-rust.|| — F. D. Frome collected the flax- 

 rust Melampsora Lini for investigation, as the Cseoma type of secidium 

 has proved to be peculiarly favourable for examination. In the spermo- 

 gonia he found that the spermatia were borne on septate-branched sper- 

 matophores, thus differing from the simple non-septate spermatophores 

 described by Blackman iov Phragmidium violaceum and Gymnosporangium 

 clavariseforme. 



In the aecidium, fusion took place between two cells at the base 



* Centralbl. Bakt., xxxii. (1912) pp. 453-9. 



t Anu. Mycol., x. (1912) pp. 153-8. 



X Bull. Soc. Bot Ital. (1912) pp. 90-3. 



§ New PhytoL, xi. (1912) pp. 129-39. 



II Bull. Torrey Bot. Club, xxxix. (1912) pp. 113-31 (2 pk.). 



