Sort REAcTIONS OF FERNS 13 
the colony of this fern in Hartland, Vermont, proved 
to be minimalkaline. It is therefore classed as a cir- 
cumneutral soil plant, although more tests should be 
made upon it. 
The crested fern, D. cristata, has a decidedly wide 
range of soil reaction, growing rarely in the New Jersey 
Pine Barrens and in the Dismal Swamp, Virginia, in 
mediacid soils (though not really thriving there) and, 
at the other extreme, occurring on damp limestone 
ledges in easterr Pennsylvania. The most luxuriant 
plants the writer has seen were growing in the slightly 
acid muck along a stream flowing through mica-schist 
rock in Maryland northwest of the District of Columbia. 
It is classed as indifferent. The variety known as 
Clinton’s fern, var. Clintoniana, has not been studied 
in the field, but there is no reason to doubt its essential 
similarity in soil requirements to the typical form. 
Samples of its soil kindly sent to the writer by Mr. CG. As 
Weatherby from a maple swamp in Avon, Connecticut, 
gave minimacid reactions; and one sent by Miss Inez 
A. Howe from St. Johnsbury, Vermont, proved to be 
neutral. 
The spinulose fern, D. spinulosa and the variety inter- 
media, are as far as observed identical in soil require- 
ments, both being wide-ranging. The typical form was 
observed above the tree line on Mt. Washington, New 
Hampshire, in mediacid soil; while in the calcareous 
soil regions of central Vermont it seemed to avoid the 
soil proper and grew on hummocks of decaying vege- 
table matter where the acidity was also high. It is 
common in the acid Dismal Swamp, Virginia. On the 
Pennsylvania 
to grow on limestone ledg 
minimalkalinity, and can only be regarded a Fig 
whole an indifferent plant. The variety intermedia is 
occasional in mediacid soil on the Coastal Plain and in 
