1917J Ayres: Nutrient Solution on Plants Groun in Sand Cultures 373 



tration were in general superior to those grown in solutions of 

 higher concentration. 



7. Flower yield as well as vegetative vigor is influenced by the 

 composition and concentration of the nutrient solution. 



8. The physiological balance of salts in the solution is an im- 

 portant factor which must be taken into consideration in con- 

 nection with the composition and concentration of the solution. 

 Growth is influenced by a combination of all of these factors. 



9. A quantitative analysis of the sand used in each pot was 

 made after the plants were harvested. 



10. Evidence of adsorption is seen in the results of the quan- 

 titative analysis of the water extract from the sand. 



11. The concentration of the nutrient solution clearly afl^ects 

 the economical use of nitrogen. 



12. High ratios of potassium added to potassium remaining 

 after growth usually occur where the dry weight production is 

 greatest. 



13. Less calcium is absorbed from solutions of low total con- 

 centration than from those which have a high total concentration. 



14. Calcium seems to be used with greater economy in solu- 

 tions where the total concentration is low than in solutions in 

 which the total concentration is high. 



Transmuted April £1, W16. 



