1908] DACHNOWSKI—TOXIC PROPERTY OF BOGS 135 
attained a height of 5-6°™. The culture media used were prepared 
as indicated for marchantia. From two to six plants were used for 
4oo°* of solution. Each experiment was continued for 7 to 10 days 
according to the amount of water transpired before renewing the 
Fic. 1—Whea Numbers 
4s in the text, p. x 
t plants from various cultures of bog water and bog soil. 
33- Six plants from each solution. 
culture Solution. The different cultures always stood side by side 
> the university greenhouse, so as to give uniform environment. 
The light conditions were the same also; direct sunlight was avoided 
by cloth Screens. In place of temperature and moisture readings, 
Measurements of the evaporation power of the air were obtained from 
