244 SUMMARY OF CUERENT RESEARCHES RELATING TO 



vacuole. A sheath of cellulose is often deposited by the host round the 

 invading haustorium. The host-cells are not killed at first, except those 

 in immediate contact with the " stroma," and their death is probably 

 due to drying, and not to any toxic secretion by the fungus. Acervuli 

 may be found on either surface of the leaf. Immediately below the layer 

 of withered cells there is formed a series of much-enlarged cells. They 

 are seen to have lost their chloroplastids and nuclei, and only a thin layer 

 of protoplasm lines the wall. This is the separation layer, and just out- 

 side them another layer shrivels, forming additional protection to the 

 healthy tissue. 



It is suggested by the author that the swelling of these " separation " 

 cells is due to increased osmotic pressure following on the breaking down 

 of amygdalin molecules into simple molecules by an emulsion produced 

 by the fungus. 



The fungus passes the winter as a stroma-like body in or outside of 

 the fallen leaves, and develops in early spring an ascigerous stage, 

 Coccomyces. The various forms are discussed and described. 



Uredineae. — B.O.Dodge and J.F.Adams* present a study of 

 Cronartmm on Myrica, the Peridermium stage of which grows on pines. 

 The chief experiments made were with the spores of jEcidium myricatum, 

 with which Chamsecyparis was inoculated. Potted plants of the latter 

 were kept in a greenhouse and sprayed with aecidiospores, but no results 

 were obtained, though it has been proved by Fromme that ^cidium 

 myricatum is connected with Gymnosporangium EUisii. Descriptions 

 are given of the various spores and of infection experiments. 



A. H. Chiversf records an epidemic of rust on mint {Puccinia 

 Menthse) in gardens at Hanover, New Hampshire. The disease was 

 first discovered about the middle of June, and by the middle of August 

 the plants were unfit for use. The season was exceptionally wet', hut 

 with the improved weather the rust seemed to have disappeared. 



Fungi of Virginia. $ — H. C. Beardslee describes several species of 

 Mycena and Omphalia that occur at Ashville, and regarding which he is 

 in some doubt owing to sUght diiferences between them and European 

 .species. Mycena stylobates is pale grey rather than white ; M. iris 

 occurs in more than one form, all with more or less of blue mycelium ; 

 species of Omphalia are next described which differ from European 

 species in more or less important particulars. 



W. A. Murrill § gives a list of fungi collected in the Blue Ridge, 

 north of Bedford, Virginia. The locality is described and the habitat 

 of the various species. One lichen, Gyrophora Muhleniergii, is recorded 

 on rocks along the summit of the mountain. Black rock owes its name 

 to this lichen. 



Battarea phalloides in Britain.! — This rare plant has reappeared 

 in Britain, in a hollow tree at Temple Guiting, in Gloucestershire, and 



* Mycologia, ix. (1917) pp. 23-9 (2 pis. and 2 figs.). 



t Mycologia, ix. (1917) pp. 41-2. 



X Mycologia, ix. (1917) pp. 30-3 (1 pL). 



§ Mycologia, ix. (1917) pp. 34-6. 



II Journ. Bet., liv. (1916) pp. 105-7. 



