Juke 26, 190S] 



SCIENCE 



987 



the seeds consisting of the testa of from four 

 to six differentiated layers and the perisperm, 

 endosperm and embryo. 



The Genesis of the Loess, a Prohlem in Plant 

 Ecology: B. Shimek. 



The influence of plants in building up sand- 

 dunes, soils, etc. The probable readvance of 

 the flora after the recession of the ice sheets, 

 viewed in the light of modem ecological ob- 

 servations. Evidence of the presence of an 

 abundant flora during the deposition of the 

 loess; snails, etc. Root-marks, iron tubules 

 and calcareous nodules of no value, as they 

 were formed after the loess was in place. 

 Comparison of the distribution of modern 

 plants and of the loess. The probable mode 

 of loess accumulation: chiefly by wind; water 

 deposition relatively insignificant. Compari- 

 son of the loess of the Missouri, the Missis- 

 sippi and the lowan border made on ecologic 

 grounds. Illustrated by slides. 

 A Hyhrid Oah: B. Shimek. 



A description of a probable hybrid oak, 

 Quercus iinliricaria palustris from Johnson 

 County. 



Notes on Peronosporales for 1907: Guy West 

 Wilson. 



The meteorological conditions of the season 

 are reviewed briefly and notes given on the 

 occurrence and abundance of both conidia and 

 oospores of sixteen species of the order. 

 A Key to the Families of Ferns and Flower- 

 ing Plants of Washington: T. C. Frye. 



The Forestry Proilem of the Prairies of the 

 West: Hugh P. Baker. 



Notes on the Routine Diphtheria Determina- 

 tion in the Laboratory : L. S. Eoss. 

 A brief comparison of work in a few labora- 

 tories. 



Isolation of Diphtheria Bacilli from Serous 

 Fluid of a Cadaver: L. S. Eoss. 

 A recent ease of such an isolation is re- 

 ported. 



The Uric Acid Ferments: E. W. Eockwood. 

 The Determination of Ferrous Iron: Nicholas 

 Knight. 



The ferric iron was determined in siderite 

 in the form of a coarse powder and again 



when very finely powdered. The fine powder 

 gave a higher percentage of ferric iron. The 

 heat produced by finely grinding the mineral 

 in the agate mortar changes a small quantity 

 of ferrous to ferric oxide. 



The Decomposition of Dolomite: Nicholas 



EJNIGHT. 



In many localities the top layer of the 

 Niagara dolomites, to the depth of a few 

 inches, appears to be decomposed and presents 

 a mealy appearance. Chemical analyses were 

 made of this to compare its composition with 

 the normal rock. A still more highly decom- 

 posed portion appearing like a ferruginous 

 clay was likewise investigated. 

 The Life of Portland Cement: G. G. Wheat. 

 The Loess of the Paha and the Biver-ridge: 



B. Shimek. 



A review of the accounts of distribution, 

 structure, composition and contents of the 

 paha and river-ridges (with special reference 

 to the loess) of McGee, Norton and others, 

 supplemented by the writer's observations. 

 The age and genesis of this loess are discussed, 

 the conclusion being that the loess is in part 

 post-Kansan, but largely post-Iowan, in the 

 latter case being often closely associated with 

 old sand-dunes. Illustrated by slides. 

 Some Peculiarities in the Elastic Properties 



of Certain Metals: K. E. Guthe. 

 An Experimental Determination of the 



Charge of an Electron hy Wilson's Method, 



using Radium: L. Begeman. 

 Nucleation According to Barus: L. Begeman. 

 Evaporation from Water Surfaces exposed to 



the Sun: A. G. Smith. 

 The Protozoa of Fayette, Iowa: Guy West 



Wilson. 



During the fall term of 1908 a number of 

 cultures were brought into the laboratory for 

 class use and as the Protozoa were rather 

 abundant notes were made on the abundance 

 and sequence of species in cultures from vari- 

 ous sources. These data are presented in the 

 form of an annotated list of species. 

 Exhihit of Photographs of Delicate Marine 



Animals taken from Life in Sea Water: 



0. C. Nutting. 



