Bui. 193, Bureau of Plant Industry, U. S. Dept. of Agriculture 



Plate III. 



Fig. 1.— Formation of Kalmia Peat, Top Layer. 

 Oak leaves of the preceding autumn. (Natural size.) 



Fig. 2.— Formation of Kalmia Peat, Second Layer. 

 Kiilinia leaves of the preceding summer. (Natural size.) 



