CONTENTS 



Page 



Determination of Acidity and Titrable Nitrogen in Wheat with 



the Hydrogen Electrode. C. O. Swanson and E. L. Tague. . i 



Ash Absorption by Spinach from Concentrated Soil Solutions. 



Rodney H. True, Otis F. Black, and James W. Kelly 15 



Nitrates, Nitrification, and Bacterial Contents of Five Typical 

 Acid Soils as Affected by Lime, Fertilizer, Crops, and Moisture. 

 H, A. NoYEs and S. D. Conner 27 



Effect of Certain Ecological Factors on the Morphology of the 

 Urediniospores of Puccinia graminis. E. C. Stakman and 

 M. N. Levine 43 



Variations and ^Mode of Secretion of Milk Solids. John W. 



GowEN 79 



New Biologic Forms of Puccinia graminis. E. C. Stakman, M. N. 



Levine, and J. G. Leach 103 



Influence of Salts on the Nitric- Nitrogen Accumulation in the 

 Soil. J. E. Greaves, E. G. Carter, and H. C. Goldthorpe. . 107 



Physoderma Disease of Com. W. H. TisdalE 137 



Injury to Casuarina Trees in Southern Florida by the Mangrove 



Borer. Thomas E. Snyder 155 



Life-History Observations on Four Recently Described Parasites 



of Bruchophagus funebris. Theodore D. Urbahns 165 



Cyanogenesis in Andropogon sorghum. C. T. DowELL 175 



Effect of Certain Compounds of Barium and Strontium on the 



Growth of Plants. J. S. McHargue 183 



Apple-Scald. Charles Brooks, J. S. Cooley, and D. F. Fisher. 195 



Angular-Leafspot of Tobacco, An Undescribed Bacterial Disease. 



F. D. Fromme and T. J. Murray 219 



Two Species of Pegomyia Mining the Leaves of Dock. S. W. 

 Frost 229 



Influence of Foreign Pollen on the Development of Vanilla Fruits. 

 T. B. McClelland 245 



A Blood-Destroying Substance in Ascaris lumbricoides. Ben- 

 jamin Schwartz 253 



Solubility of the Lime, Magnesia, and Potash in Such Minerals 

 as Epidote, Chrysolite, and Muscovite, Especially in Regard to 

 Soil Relationships. R. F. Gardiner 259 



A Field Study of the Influence of Organic Matter upon the Water- 

 Holding Capacity of a Silt-Loam Soil. Frederick J. Alway 



and Joseph R. Neller 263 



(in) 



