1906] TRANSEAUBOGS OF THE HURON RIVER VALLEY 



2 3 



that the experiments should extend over a series of years in the 

 case of the shrubby forms, the problem becomes still more com- 

 plicated. 



Cold bog water 



Cold nutrient solution 



Warm nutrient solution Warm bog water 



FIG. 12. Average plants from the several cultures of Indian corn. From photo- 

 graphs. 



In order to test the relative effects of humous acids (of the con- 

 centration found in the bogs of this vicinity) and low substratum 

 temperatures, experiments were made in the form of water cultures 



