1906] TRANSEAUBOGS OF THE HURON RIVER VALLEY 27 



A. Drained warm bog substratum 



B. Drained cold bog substratum 



C. Undrained warm bog substratum D. Undrained cold bog substratum 



E. Dry sand 



F. 



FIG. 14. A, B, C, D, E, camera drawings of leaf sections resulting from cultures 

 in the five conditions named. Xi35- E, diagrams showing average length and 

 breadth of leaves. 



