BUMMARV OF CURRENT RESEARi HES RELATING TO 



Research on Uredineae.* — E. Dittschlag lias conducted a research on 

 the various life-stages of Puccinia Falearise, an autcecious CJredine. The 

 mycelium with aninucleate cells passes the winter in the host-plant. 

 The time of teli utospore germination, and of new infection by the sporidia 

 is ii,, i known. The Bpefmogonia appear first in large numbers, Later the 

 aecidia are formed. These latter begin by the formation of a thick coil of 

 mycelium from which arise hyphse towards the epidermis, the end cells 

 becoming sexual or fertile cells. When two of these cells come into 

 contact their walls 'partly disappear and they fuse together; possibly 

 this takes the place of a previous fertilization by spermatia. The 

 presence of the so-called sterile cells cannot always be proved. After 

 the fusion 2-nucleate spore-mother-cells are cut off, and finally the 

 sports and the intercalary cells degenerate. At an early stage the pe- 

 ndiiini is formed, the walls of the cells composing it become thickened, 

 audit forms a protection for the aecidium. The spores reinfect the 

 same host or an individual of the same species. A bi -nucleate mycelium 

 is formed, and finally teleutospores. Probably the teleutospores pass the 

 winter on the decaying leaves and germinate in early spring. Dittschlag 

 discusses very fully the results arrived at by different workers in the 

 same held, and their views on the nature of the cell fusion. He rejects 

 the view that any sexual differentiation can be proved in the two cells 

 as they an- frequently alike in size, though occasionally the one is larger 

 than the other. It was not possible to prove the constant presence 

 of Bterile end-cells (the trichogyne-cells). When such were present they 

 were found on the ends of both the copulating cells. As regards 

 nuclear division the conjugate nuclei divide simultaneously, and the 

 different stages were followed, but the number of chromosomes could 

 not be accurately determined. 



Conidial Fusion in Ustilago Tragopogi-pratensis.t — Harry Federley 

 finds that two types of conidia are formed on the germination of 

 the spores : (1) large conidia which join in pairs and never bud out ; 

 and (2) smaller conidia. which do not at first join in pairs, but which 

 increase by budding. So long as nourishment is provided the budding 

 process continues; when the medium becomes exhausted the conidia 

 unite. In the larger paired conidia there is no distinction of size; the 

 nucleus of the one passes over to the other and the two nuclei fuse. 

 The protoplasm follows later than the nucleus. A previous fusion of 

 nuclei bakes place in the Ustilago spore, but which of these fusions is 

 sexual has noi been determined by the author. 



German Ag-aricaceae.J— A. Ricken has published a German Flora 

 "! i hoe larger fungi, in semi-popular language, so that it may be useful 

 to the laity as well as to professional mycologists. He has provided 

 German names for all the species in addition to" the Latin names. The 

 coloured plates represent about half of the species recorded. 



lakt., xxviii. (1910) pp. 473-92 (3 pis. and 7 figs.). 

 I '"' k - Naturf.-och Lak., Helsingfors.xxi. 7 (1903) pp. 24-26. 



I Die Blatterpilze (Agaricacese) Deutschlands und der angrenzender Lander. 

 Leipzig : Weigel (1910) lief. 1, 32 pp. (8 col. pis.). 



