234 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Biology of Sclerospora.* — Two species of this genus, Sclerospora 

 graminicola on Setaria viridis and Sclerospora macrospora on a number 

 of grasses and cereals, are very prevalent in the valley of the Po, where 

 they have been collected by Yittorio Peglion, the author of the paper. He 

 notes that the spores of the first species are not congregate, but lie in 

 loose masses between the fibro- vascular bundles and the outer cortex ; 

 they are thus easily scattered by the wind. 8. macrospora has also a wide 

 distribution, but it occurs somewhat rarely. The oospores are congregate 

 and less liable to be dispersed. No conidia have been observed in the 

 genus. The primary effect of the fungus on the host-plant is to increase 

 the vegetative development, and the plants attacked have a brighter green 

 colour than the normal plants. The relation between host and parasite 

 is thus of a somewhat mutualistic nature at the beginning. When seed- 

 time arrives the damage done by the parasite becomes more apparent ; 

 the seeds are deformed and incapable of germination. Cattle eat the 

 grasses infected with Sclerospora very readily and without any bad results. 

 Figures are given of deformed ears of cereals and of the abnormally 

 developed leaves of Glycerki festucseformis, a witches'-broom being formed 

 by the parasite. 



Notes on Saprolegnia.f — A. E. Lechmere claims to have produced 

 on one and the same pure culture of Saprolegnia the non-sexual types of 

 fructification of a series of closely related genera. Lechmere describes 

 his cultures and the different growths. 



Fungus of House-fly.:}: — Gr. Gordon Hewitt discusses this fungus, 

 Empusa Muscse, along with the parasites that attack Musca domestica in 

 his paper on the structure, development and bionomics of the House-fly. 

 A large proportion of the flies that have survived till the autumn are 

 killed off by this fungus, of which the sporophores bud off and ejaculate 

 terminal conidia ; these conidia alight on another insect, penetrate the 

 body and produce mycelium with further conidia. Resting spores that 

 would carry the fungus over the winter have been described, but some 

 doubt still exists as to their occurrence. 



Ascocarp of Leotia.§ — William H. Brown has made a microscopical 

 study of the ascocarp of L. lubrica and L. chlorocephala, more especially 

 of the ascus-formation. In the youngest specimen of L. lubrica that the 

 writer found, the supposed ascogonium — a large cell of which the 

 contents were vacuolated and degenerated — gave rise to a number of 

 large hyphse which extended upwards towards the tip of the ascocarp. 

 At the tips of these ascogenons hyphae, asci are formed in several different 

 ways . In some cases a typical hook is formed in which the two nuclei 

 of the penultimate cell may fuse to form the nucleus of an ascus, or they 

 may divide and give rise to the nuclei of another hook. The terminal 

 cell grows down and fuses with the antepenultimate cell, and the fused 

 cell may form an ascus or give rise to still another hook. Other hook 

 formations are also described. 



* Centrabl. Bakt., xxviii. (1910) pp. 580-9 (G figs.). 



t New Phytologist, ix. (1910) pp. 305-19 (2 pis.). 



% Quart. Journ. Micr. Sci., liv. (1910) pp. 371-4 (pi. 22 and figs. 15-17;. 



§ Bot. Gaz., 1. (1910) pp. 443-59 (47 figs.). 



