404 BOTANICAL GAZETTE [may 



ii. In agricultural soils used as adsorbents the presence of the 

 adsorbed unknown toxins replaces normal growth by an abnormal 

 retardation. Fertility is restored through aeration, that is, after time 

 enough has elapsed for the oxidation of the injurious bodies. 



12. The contaminated condition of agricultural soils and the con- 

 sequent decreased physiological activity of the plants grown in them 

 still further indicates that xerophily cannot be due to acidity, lack of 

 oxygen, low temperature, etc., of the soil substratum; that is, the 

 factors heretofore cited are only in part the cause of xerophily. 



In view of the evidence presented above, the writer believes that 

 these facts in the action of bog water upon soils justify the conclusion 

 that there are present in bog water and in bog soils injurious substances 

 which are, at least in part, the cause of xerophily in plants, and of 

 decreased fertility in bog soils. 



Grateful acknowledgment is made to Professors McCall and Vi- 

 vian, of the Agricultural College of the university, for the facilities 

 of their laboratories, which were freely and courteously placed at the 

 writer's disposal. 



Ohio State University 



Columbus, Ohio 



LITERATURE CITED 



KMA 



2 



I905. 



. Briggs, L. J., On the adsorption of water vapor and of certain salts .in aqueous 

 solution by quartz. Am. Jour. Phys. Chem. 9:617-640. i9°5- 

 3. Comey, A. M., Dictionary of chemical solubilities. 1896. ^ 



4- Clark, F. W., The data of geochemistry. U. S. Geol. Survey, Bull. 33 • 



1908 



5. Dachxowski, A., The toxic property of bog water and bog soil. 



Bot. 



Gazette 46:130-143. 1908. 



vjAz,£,ii£. 4u: 130-143. 1900. O g. 



6. Hall, A. D., Theories of manure and fertilizer action. Science N. 

 617-628. 1908. . _. ^ p 



7. Hopkins, C. G., and Pettit, J. H., The fertility in Illinois soils. 



Exper. Stat. Bull. 123:251-255. 1908. . Ex ^ r . 



8. Huston, H. A., and Bryan, A. H., Swamp muck. Rept. Ind. *& • 



Stat. 1900. sdence 



9- King, F. H., Toxicity as a factor in the productive capacity ot so.is. 



N. S. 27:626-635. 1908. 



