ROWLEE: RELATION OF MARL PONDS AND PEAT BOGS 413 
occur at Tully and near Cortland. The limestone outcrop in these 
regions accounts for a continuous supply of water impregnated with 
lime. The peat bogs with the greatest thickness of marl under them 
occur not far from this same limestone belt, while the peat bogs with 
little or no marl are usually farthest from the limestone outcrop. 
It does not seem at first thought as though Chara could be the 
agency causing the radical change in the history of the vegetation of 
the pond and the accumulations in these depressions. In so far as 
vegetation is concerned calcium carbonate is relatively insoluble. 
Fic. 3. Transition bog near Cortland, N. Y. A thick bed of marl is over- 
laid with about four feet of fibrous peat. Marl was excavated from the hole in the 
foreground. Sedges are prominent in the vegetation now covering the surface of 
the bog. 
Not so, however, is the lime in spring water. The water with available 
(more or less) free lime is what Chara takes in and in its life processes 
converts into calcium carbonates secreted in its walls. That an im- 
mense amount of lime is converted is shown by the bulk of marl in the 
ponds. Where the amount of the lime in the original soil was not 
large, rain water constantly tended to wash it out and in the course of 
time the lime content of the water would be decreased. The ponds 
were artesian pools fed by these springs and as the character of the 
water changed there was, if our theory is correct, a corresponding 
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