'"1 
V-' 
CONTENTS 
Page 
Aspergillus niger Group. Charles Thom and James N. Currie. i 
Some Effects of the Blackrot Fungus, Sphaeropsis malorum, upon 
the Chemical Composition of the Apple. Charles W. Cul¬ 
pepper, Arthur C. Foster, and Joseph S. Caldwell . 17 
Formation of Hematoporphyrin in Ox Muscle during Autolysis. 
Ralph Hoagland.*. 41 
Comparison of the Nitrifying Powers of Some Humid and Some 
Arid Soils. C. B. Lipman, P. S. Burgess, and M. A. Klein. . 47 
Immobility of Iron in the Plant. P. L. GilE and J. O. CarreRO .. 83 
Effects of Nicotine as an Insecticide. N. E. McIndoo. 89 
Acidity and Adsorption in Soils as Measured by the Hydrogen 
Electrode. L. T. Sharp and D. R. Hoagland . 123 
Life History of Habrocytus medicaginis, a Recently Described 
Parasite of the Chalcis Fly in Alfalfa Seed. Theodore D. 
Urbahns.... 147 
Daily Transpiration During the Normal Growth Period and Its 
Correlation with the Weather. Lyman J. Briggs and H. L. 
Shantz. 155 
Studies of Spongospora subterranea and Phoma tuberosa of the 
Irish Potato. I. E. Melhus, J. Rosenbaum, and E. S. 
Schultz. 213 
Growth of Parasitic Fungi in Concentrated Solutions. Lon A. 
Hawkins. 255 
Freezing-Point Lowering of the Leaf Sap of the Horticultural 
Types of Persea americana. J. Arthur Harris and Wilson 
Popenoe. 261 
Grain of the Tobacco Leaf. Charles S. Ridgway . 269 
Host Plants of Thielavia basicola. James Johnson. .. 289 
Chemical Composition, Digestibility, and Feeding Value of Vege¬ 
table-Ivory Meal. C. L. Beals and J. B. Lindsey . 301 
Rosy Apple Aphis. A. C. Baker and W. F. Turner . 321 
Use of Two Indirect Methods for the Determination of the Hygro¬ 
scopic Coefficients of Soils. F. J. Alway and V. L. Clark. . 345 
Correlation Between the Size of Cannon Bone in the Offspring and 
the Age of the Parents. Christian Wreidt . 361 
Laspeyresia molesta, an Important New Insect Enemy of the 
Peach. A. L. Quaintance and W. B. Wood. 373 
Energy Values of Red-Clover Hay and Maize Meal. Henry Pren¬ 
tiss Armsby, J. August Fries, and Winfred Waite Bra- 
man. 379 
(m) 
