84 AMERICAN FERN JOURNAL 
that it will be found that local conditions, such as may 
be found in a very deep cool ravine, for example, would 
account for its being lower. A correspondent in Eurepe 
once wrote me that in central Europe it is also confined 
to comparatively high altitudes. In more northern 
latitudes as in Labrador it is, of course, found even as 
low as at sea level, but this is also true of most alpine 
plants. 
The special point in mind is the mistake often made, 
as I did for years, of trying to find dilatata in every 
broad leaved intermedia in any lowland woods. When 
once seen it is recognized as a very distinct thing and 
even when transplanted to lower levels it retains its 
distinctive characters. I brought Blue Mountain plants 
of dilatata to the New York Botanical Garden in 1908 
which are still growing there and easily distinguishable. 
Then, too, dilatata is the first of the spinulose ferns to 
feel the effects of frost which causes the leaves to wither 
and turn brown in September. 
Onoclea sensibilis. Common along Third Lake Creek, 
but becoming less so as the operations of beavers are 
continually raising the level of more and more of this 
stream and the sensitive fern or, as Mr. Scott calls it, 
the bull-moose fern, usually occupies stretches of grassy 
bank. I remember seeing one considerable growth of 
Onoclea almost entirely covered with water due to a 
recent addition to the height of the next dam below. 
After a short period of this treatment even the bull- 
moose fern succumbs. Some of the beaver dams are 
so extensive and go placed that large tracts of land 
have been flooded with the consequent death of many 
acres of trees. The beavers were introduced by the 
state some years ago and are still protected by penalty 
of a heavy fine. 
P olypodium vulgare. Almost every large boulder in 
moist upland woods is covered by large sods of poly- 
