II CONTENTS. [Vol.43 



Page. 



The sun as a source of power 117 



Rainfall data and deterndning road conditions, Sldpnian 117 



Average free-air conditions at Drexel Aerological Station, Nebr., Gregg — 118 



Relation of winds to temperature in central Ohio, Martin , — 118 



Smoke formations in air drainage, Halleubeck 118 



Spring frosts 118 



Weather observations, Franklin 119 



Thunderstorms 119 



Hail 119 



Monthly Weather Review 119 



Weather review for 1916 and 1917, Edmond 120 



Climatic conditions, Letteer 120 



Meteorology report for 1918, Hepner 120 



SOILS FERTILIZERS. 



Soil and fertility investigations, McCall et al 121 



Importance of soil investigations to agriculture, Konig 122 



On the angle of repose of wet sand, Webster 122 



Soil survey of Hamilton County, Iowa, Espe and Lindley 122 



Soil survey of Sargent County, N. Dak., Huttoii et al 123 



Soil survey of Waupaca County, Wis., Geib et al 123 



Development of unused lands, Cory, Hanna et al 123 



Relation of bacteria to soil productivity. Beavers 124 



Influence of time of year on nitrification, Lemmermann and Wichers 124 



The occurrence of " volutin " in Azotohacter chroococcum, Schmidt 124 



Handling farm manure, Duley 124 



Effect of fertilizer salts treatments on soil extracts, Spurway 124 



Action and use of new fertilizers, Schneidewind 125 



Calcium cyanamid, Miege 126 



Potassium nitrate and anmionium sulphate from raw potash, Hampel 126 



Trona potash : A progress report, Blackwell and Collings 126 



Potash and bromin in Texas lakes 127 



Phosphatic slags, Vandormael 127 



Method for rendering insoluble phosphates available, Keitt and Murray 127 



Liberation of soil potash by calcic and magnesic materials, Maclntire 127 



The lime factor in permanent soil improvement, I, Lipnian and Blair 128 



The lime factor in permanent soil improvement, II, Lipman and Blair 128 



Peat industry reference book, Gissing 129 



Inspection of fertilizers in INiissouri, 1919, Mumford and Haigh 129 



Fertilizer registrations for 1920, Cathcart 129 



Commercial fertilizers, Robinson 129 



AGRICULTURAL BOTANY. 



• 



Floras of islets outlying from Stewart Island (New Zealand), Willis 129 



The role of sedges in some Colorado plant communities, Ramaley 129 



Ecologic subterranean anatomy of some plants in central Iowa, Hayden 130 



Some observations on the tuber of Phylloglossum, Osborn " 130 



Sprouting of woody plants and inliuence of external factors, Ktihn 130 



Pressure and water utilization in transpiring shoots, Nordhausen 130 



Osmotic pressures in potato plant at various stages, Lutman 130 



Viability of detached root-cap cells, Knudson 130 



Studies on growth and change of f(n-m in vegetating points, Schiiepp 131 



Some factors in the chemical stimulation of Asiicrfiillus niger, Steinberg 131 



Infiueuce of phosphates on a crotonic acid in plants, Skinner and Reid 131 



Influence of light on stomata and transpiration, Gray and Peirce 131 



Cell growth in relation to supply of energy by protoplasts, Janse 131 



The structure of protoplasm, Harper 132 



Origin and nature of mucilage in cacti and other plants, Lloyd 132 



Anthocyanin of Beta vulgaris, Andrews 132 



Chlorophylless wheat plants, Kalt 132 



Temperature-coefficient of photosynthesis : A reply to criticism, Smith 132 



Theory regarding phototropism, Bremekamp 132 



The transmission of phototropic stimulation, Patll 132 



Studies on symbiosis between Ardisia crispa and its bacteria, II, Miehe__ 133 



