400 



BOTANICAL GAZETTE 



[may 



ments were repeated later by the wire-basket method with the same 

 results. Six wheat seedlings w r ere transplanted in a row in the soil 

 of each pot. In identically the same 



manner 



cultures with the untreated soils was prepared to serve for comparison 

 with the behavior of wheat seedlings in the contaminated soils. The 

 filled pots were then weighed and placed in the greenhouse where 

 they stood side by side. Direct sunlight was avoided by cloth screens. 

 Only one of the experiments need be given, and Table V gives a 

 summary of the results obtained with bog water collected September 

 12, 1908. The percentage increase is calculated upon the basis of 



zero (o), considering them as unity for the 



marked 



respective series. 



(fig 



J 



experiment. 



TABLE V 

 Adsorption of bog toxins by soils 



SOLUTION 



AVERAGE LENGTH IN CM. 



Tops 



Roots 



Percentage increase 



Transpiration 



Greer weight 



i. Bog water untreated 



2. Bog water quartz-filtered.. . 



5. Bog water clay-filtered 



8. Bog water humus-filtered. . 



3. Contaminated quartz soil. . 



6. Contaminated clay soil. . . . 



9. Contaminated humus soil... 



4. Control quartz soil. ....... 



7. Control clay soil 



10. Control humus soil. ....... 



15.8 

 20.8 

 19.9 



30-5 

 22. 



22.2 



21.9 



24.7 



26. 



30-7 



5-3 

 42. 



11. 4 

 15.6 



12.3 

 6.6 



6.2 



9.6 



11. 7 



13-5 



c 



338. 



154. 



805. 



Dry weight 



• • 



• • 



• • 



• • 



134- 



68. 

 220. 

 o 

 o 

 o 

 8. 



25- 

 86. 







5*. 



11. 



84- 

 











20. 



5- 



55- 



Again it is evident that the addition of solids has increased the 



tolerance of the seedlings to bog water. 



The improvement was 



experimentation 



The presence 



of the toxic bodies in small amounts exerted a noticeable stirnula in,, 

 effect, while the plants in the control bog water gave every i ° diC ^\ 

 that they would be unable to survive an exposure of a normal grew 1 



point has been repeatedly tested also 



period. 



mentioned 



111 liciu-wuiK. ±1 seems as n tne routs, <uiu w^v,w«,* v — 



roothairs, of the plants in the untreated bog water served as 



_ minute 

 dsorbing 



surfaces. 



u trie pianis in tne untreated vug wa^ *• • . 



The roots are brownish in color and jelly-like in con 



