suggestions may already exist in unpublished' or published 

 records. 



It is not necessary that the plan of subdividing by solution 

 types should necessarily involve the testing of all the solutions 

 of a given type at once. The solutions may be graphed on the 

 triangular diagram and then the diagram may be arbitrarily 

 divided into two or more regions, each region being considered 

 separately. Thus, the first ten or eleven solutions of any one 

 of the tables as here given may be considered as a first group, 

 the remaining solutions of that type constituting a second group, 

 to be tested after the first. 



An experimental comparison of the physiological properties 

 of any single solution given in tables I to VI, with the control 

 solution, will constitute a valuable step toward the working out 

 of the plan. It is hoped that many workers who are not able to 

 devote a great deal of time to this project will nevertheless join 

 in the work, even by testing a single solution. Indeed, the study 

 of the relation of climatic conditions to growth may be greatly 

 advanced if a large number of experimenters will carry out cul- 

 tures with the control solution alone. If one could do no more, 

 it would be well worth while to get the plant measurements for a 

 number of control cultures, at any time during the year, of course 

 obtaining at the same time the climatic data mentioned in the 

 plan. The growth of wheat in Shive's best solution for this plant 

 might thus become a sort of common criterion by which different 

 climatic complexes (for different seasons and for different sta- 

 tions) might be compared, in terms of their influence on the 

 physiological processes of wheat. 



As the work goes forward the committee will furnish further 

 suggestions as to the subdivision of the plan, upon request. 



REPORTS OF RESULTS. 



As has been said, all cooperators are strongly urged to send 

 to the committee all results obtained just as promptly as possible. 

 Forms for such reports will be supplied to cooperators on 

 request. 



SUSCEPTIBILITY TO ATTACK BY BACTERIA OR FUNGI. 



Emphasis has been recently placed on the observed fact that 

 a poorly balanced fertilizer treatment may not only produce 

 smaller or less well-developed plants than does a more nearly 

 perfect treatment, but such poor treatment may frequently also 



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