468 BOTANICAL GAZETTE [DECEMBER 
Even if stumps occur in place throughout the deposit, they 
cannot be cited as incontrovertible evidence of subsidence until 
we make sure that nature can in no other manner produce such a 
succession of stumps in place. It has occurred to me that floating 
bogs bearing trees might sink as new accumulations of material in 
place would be carried downward to the bottoms of ponds or lakes. 
Several botanical friends to whom I have appealed tell me that 
buried stumps might well be produced in this manner. PEN- 
HALLOW” describes a bog which, according to his interpretation, 
has had such a history. Surely then we are justified in doubting 
the assumption that stumps in place deep down in a kettle hole 
bog are conclusive proof of a change in the relative level of land 
and sea. 
But if we granted that the phenomena cited by BARTLETT could 
be accepted as a proof of coastal subsidence, we must still ask for 
some satisfactory evidence of the age of the lower part of the 
deposit before we can accept it as a proof of recent subsidence. 
The upper part of the deposit may well be of recent date, and yet 
not be the result of coastal subsidence. If any part of the deposit 
proves subsidence it is the lower part, which cannot have been 
affected by changes in tidal levels. But are we sure that this lower 
part is of recent date? Surely those familiar with the antiquity of 
some of the peat bogs of Europe, in which wood and other substances 
are still well preserved, will hesitate to affirm that the lower part of 
a given peat bog must be of recent date as here defined. 
When critically examined, neither the botanical nor other 
evidence of recent coastal subsidence seems to me conclusive. 
On the other hand, the physiographic evidence, so far as I have 
been able to analyze it, indicates a long period of coastal stability. 
The evidence in favor of stability I have already briefly outlined 
elsewhere, and I will present a more detailéd account of it in 4 
forthcoming report on the Shaler Memorial investigation of shore 
line changes along the Atlantic coast. 
CoLuMBIA UNIVERSITY 
New York City 
- PENHALLOW, D. P., A contribution to our knowledge of the origin and develop- 
ment of certain marsh lartds on the coast of New England. Roy. Soc. Canada, Proc. 
and Trans. III. 14:33-34. 1907. 
