434 EXPERIMEKT STATION RECORD. 



It was found in his experiments, whicli were carried over 4 years, that 

 plants may l)e induced to live as parasites when they are subjected to the 

 necessity of securing their nutrition from the host and also of maintaining 

 their turgidity as a necessary condition of growth and other constructive proc- 

 esses. The change from an autophytic to a parasitic condition is apparently 

 one that may be readily made by many species of plants. 



FIELD CROPS. 



Proceeding's of the American Society of Agronomy (Proc. Amer. 8oc. 

 Agron., 1 (1907-1909), pp. 238, figs. 9). — This volume contains in condensed 

 form the minutes of meetings of the American Society of Agronomy, held in 

 Chicago, Ithaca, Washington, and Omaha, together with 39 of the 69 scientific 

 papers presented at these meetings, as follows: 



Development and Proper Status of Agronomy, by M. A. Carleton ; The Neces- 

 sity for Greater Care in the Identification of Crop Varieties Used in Experi- 

 mental Work, by C. V. Piper ; The Testing of Varieties as Foundation Work 

 in the Improvement of Farm Crops, by R. A. Moore, by A. T. Wiancko. and by 

 A. M. Ten Eyck ; Some Desirable Precautious in Plat Experimentation, by 

 H. J. Wheeler ; The Interpretation of Field Experiments, by C. E. Thorne ; The 

 Size of Experiment Plats for Field Crops, by F. W. Taylor ; Some Experiments 

 to Determine the Uniformity of Certain Plats for Field Tests, by J. O. Morgan ; 

 The Use of Row Plantings to Check Field Plats, by V. L. Cory ; Breeding, 

 Multiplying, and Distributing Improved Seed Grain by the Experiment Station, 

 by A. M. Ten Eyck ; Plat Arrangement for Variety Experiments with Com, 

 by L. H. Smith ; Selection in Vegetatively Propagated Crops, by W. J. Spillman ; 

 The Row Method and the Centgener Method of Breeding Wheat, Oats, and 

 Barley, by C. P. Bull ; The Relation Between the Size of Seeds and the Yield of 

 Plants of Farm Crops, by C. A. Zavitz (see below) ; Methods of Studying the 

 Relative Yielding Power of Kernels of Different Sizes, by W. M. Jardine; 

 The Relation of Wheat to Climate and Soil, by T. L. Lyon ; Some Experiments 

 in Breeding High-nitrogen Wheat, by R. W. Thatcher ; Factors which Determine 

 the Composition of Wheat, by R. W. Thatcher ; Delayed Germination of Durum 

 Wheat, by L. R. Waldron ; Experiments in Growing Alfalfa from Seed Secured 

 from Different Sources, by J. M. Westgate, and by A. Mackay ; Sowing Alfalfa 

 and the Common Clovers with and without a Nurse Crop, by R. A. Moore ; The 

 Soy Bean as a Farm Crop, by C. A. Mooers; Basis for Estimating the Yield 

 of Hay, by W. J. Spillman; Weed Control by Means of Chemical Sprays, by 

 H. L. Bolley; Value of the Field Study of Soils, by G. N. Coffey; Physical 

 Principles of Soil Classification, by G. N. Coffey; Methods of Soil Surveying, 

 by E. L. Worthen; Relation of Soil Surveys to Crop Surveys, by E. O. Fippin; 

 How Can Our Soil Surveys be Made of Greater Value to Agriculture? by 

 W. H. Stevenson and by A. M. Ten Eyck; Increase in the Practical Efficiency 

 of the Soil Survey, by E. O. Fippin; Instruction in Soil Physics, by A. G. 

 McCall ; The Soil as a Limiting Factor in Crop Production, by W. J. Spillman ; 

 Availability of Soil Nitrogen in Relation to the Basicity of the Soil and to the 

 Growth of Legumes, by T. L. Lyon; Some Conditions Affecting Nitrification 

 in Dunkirk Clay Loam, by J. A. Bizzell ; Some Results with Lime on Missouri 

 Soil, by M. F. Miller; and Some Soil Problems in Oklahoma, by L. A. Moorhouse. 



The relation between the size of seeds and the yield of plants of farm 

 crops, C. A. Zavitz (Proc. Amer. Soc. Agron., 1 (1907-1909), pp. 98-101,).— 

 This paper presents full data obtained in tests of the yielding power of large, 

 medium, and small seeds of oats, barley, field peas, spring and winter wheat, 

 mangels, sugar beets, swedes, fall turnips, field carrots, rape, and potatoes. 



