448 EXPERIMENT STATION RECORD. 



and V. magellatiica, on Taplirina-diseasecl leaves of N. antarctica bicrenata. 

 Attention is also called to the constant association of Microsphwra aim with 

 Mcidium magcllanicum on Berberis buxifoUa. 



Three interesting species of Claviceps, F. L. Stevens and J. G. Haxl {Bot. 

 Gas., 50 (WLO), No. 6, pp. 460-^63, figs. S).— By planting the hibernated 

 sclerotia of Sclerotium paspali in moist earth, the authors obtained the as- 

 c-igerous stage of two species of Claviceps which are described as new, viz, 

 V. paspali and C. rolfsii, both producing yellow to gray, globose-roughened 

 sclerotia in the spikes of Paspalmn Iwve and P. dllatatum. 



In the same manner the ascigerous stage of a third Claviceps was obtained 

 from the smooth, white to dark brown or black, nearly conical sclerotia which 

 were found protruding from the basal ovulate portions of the spikes of 

 Tripsacum dactyl oidcs. This is also described as a new species, C. tripsaci. 



Fusarium epidemics on cucumbers, peas, and grain, E. Voces {Deut. 

 Landw. Presse, 31 {1910), No. 93, pp. 1012-1014, figs. 5). — The author claims 

 that in years which are noted for epidemics of Fusarium diseases, the weather 

 conditions, such as prolonged wet and clovidy periods, are the determining 

 factors, producing a weakened condition of the host plants which permit the 

 parasitic fungi to gain a foothold and spread rapidly in the tissues of the host. 



In the case of the Fusarium on the wheat, where many of the spikes were 

 partially or totally blighted, being either entirely sterile or containing many 

 shriveled grains, a microscopic examination of the sections of grain from the 

 diseased stalks showed the presence of mycelium in the starchy portions of 

 the endosperm. Experiments also showed that sound grains could be infected 

 by contact with diseased grains, and that infection could also be produced 

 through spores. 



On the spongy bodies, spheres, and globular bodies present in the cells 

 of bracken (Pteris) and potato, A. S. Horne (Centbl. BaTct. [etc.], 2. Abt., 

 28 {1910). No. 12-15, pp. 403-408, pis. 3). — The author discusses the structure 

 of certain globular bodies found in the young cells of the growing points of 

 Pteris and potato, which exhibit a remarkable form resemblance to Plasmodia, 

 sporangia, spores, etc., of certain chytridiaceous organisms. 



Conservation of the purity of soils in cereal cropping, H. L. Bolley 

 (Science, n. ser., 32 {1910), No. 825, pp. 529-541). — Attention is called to the 

 deterioration in yield of wheat, flax, and oats in many sections of the north- 

 western United States, due in most instances, it is claimed, to the unsanitary 

 methods of handling the soil, the crop, and the seed. 



It is claimed that the older wheat fields are sick throughout, or in large 

 areas, in exactly the same sense that certain cotton lands are sick with root 

 rots, or flax lands flax-sick. This wheat-sick soil condition is said to be due 

 to at least 5 parasites which enter the seed wheat before maturity and are 

 carried over to the next generation. When once introduced into the soil they 

 persist there for a number of years, doing more or less damage according to 

 weather, soil, and fertilizers. 



It is stated that these wheat-sick soils are found in every county in North 

 Dakota, and that they extend into South Dakota, Minnesota, Indiana, Wash- 

 ington, California, Kentucky, New York, and Alberta, Manitoba, and Ontario. 

 The parasites have been found in seed imported from Russia, Italy, France, 

 and Algeria, and have been taken from samples of stems and roots from almost 

 every important wheat area of Minnesota and North Dakota. 



It is claimed that the 3 most destructive parasites, taken in their order, are 

 one or more species of Plelminthosporium, Fusarium, and Colletotrichum, all 

 of which are found on the roots, leaves, stems, and seeds of wheat, while 



