INTRODUCTION. 



This project aims to test a large number of combinations of the 

 necessary chemical elements, to find out what combinations give 

 the most satisfactory growth of the plants considered. Different 

 phases of the development of the plants are to be treated sepa- 

 rately, to bring out any changes in the •nutritional requirements 

 that may supervene as gi*owth proceeds. As many different com- 

 plexes of climatic conditions as are practicable are to be tested, 

 to find out in how far the salt requirements may depend upon 

 climatic conditions. It is planned to find out just what sets of ^ 

 salt conditions give the best growth for each type of climatic 

 complex. 



The project thus contemplates a very thorough experimental 

 study of the physiological possibilities of the plants dealt with. 

 Just as the atomic weights of the chemical elements need to be 

 known with considerable precision before their relations to their 

 surroundings may be satisfactorily studied, so the physiological 

 characteristics of agricultural plants need to be known before 

 scientific agriculture may progress very far. 



The cooperative feature of the project aims to secure a large 

 body of comparable data as rapidly as possible. A large number 

 of research workers acting simultaneously will be able to test 

 the numerous possibilities in a comparatively short time, and the 

 fact that all employ the same standard methods should make all 

 of the results fit into one general whole. 



The following outline, which is planned to be extended and 

 improved later, has been elaborated through consultation with 

 a large number of specialists in this sort of work. It is hoped 

 that the essentials of the method here described will be followed, 

 since likeness of method is the prime consideration in work of 

 this sort. When alterations of the plan seem necessary the other 

 cooperators should be informed and an agreement reached 

 through the committee. Correspondence regarding the work 

 should be addressed to Dr. B. E. Livingston, Laboratory of Plant 

 Physiology, the Johns Hopkins University, Baltimore, Md. 



DR. A. G.'McCALL, 



THE PLAisA^WJOgi^ H^SeM"- investigations, 



UNIVERSITY OF MARYLAND 

 The first and most important plant for the present purpo'se is 



wheat, and a supply of seed of the ":fe^'rli&'S^ ^?fkj^% spring 



wheat was obtained by purchase from Professor Leith, of the 



Wisconsin Agricultural Experiment Station. Cooperators will 



