120 AMERICAN FERN JOURNAL 
of the Academy of Natural Sciences of Philadelphia were 
then examined, and at least six specimens agreeing more 
or less definitely with this hybrid were found to be there 
included. They came from McCall’s Ferry, Cully and 
Muddy Run, in Lancaster County, and from York Fur- 
nace in York County, across the river. These localities 
all lie in an area less than 20 kilometers long by 3 km. 
wide. It is noteworthy that both parents of the hybrid 
are present at all of the places just listed; and although 
A. Bradley was not observed by Mr. Pretz at the local- 
ity from which his specimens came, it grows in the gen- 
eral vicinity. 
The chief features on which the identification of this 
hybrid were based are tabulated here, with the corres- 
ponding data for the parent species. 
TABLE 1. COMPARISON OF THE FEATURES OF THREE 
ASPLENIUMS 
A. pinnatifidum A. gravesii Bra 
Stipe green, often brown, rarely brown. throughout: 
brown below green above its length 
Frond pinnatifid to pinnate, pinnatifid pinnate through- 
pinnate above out 
Rachis broad, green fairly broad, green; narrow; lower 
ften brown below half brown, up- 
per half green 
Margin wibwsgex crenate-dentate ie ass 
Texture thie medium 
i ran brown dark brown ure brown 
In spite of a rather considerable variability of the 
above three ferns, the hybrid can be readily recognized 
in practically every case, the dark brown sori, brown 
stipe, and intermediate degree of cutting of the margin 
being the most striking features. 
Tests made upon the soil adhering to the roots of A. 
gravesit in several of the herbarium specimens mentioned 
and subsequently at the actual localities (visited in 
July 1920), have shown the specific acidity of 100 to 300 
in every case. It is noteworthy that these values are 
