#4 AMERICAN FERN JOURNAL 
striking contrast to its soil at certain other stations, 
which is a black, friable leafmold. Both the clay from 
South Pittsburg, Tennessee and the leafmold from James- 
ville, New York, yielded on testing practically neutral 
reactions, indicating the correctness of the usual classifi- 
cation of this fern as a calcareous soil plant. Although 
its distribution is of course largely controlled by climatic 
conditions, it is noteworthy that the results show it to 
grow in soils of divergent physical but uniform chemical 
character. 
Camptosorus rhizophyllus (Asplenium rhizophyllum) 
has been found throughout Pennsylvania and adjoining 
states to be most frequent and luxuriant in cireumneutral 
soils, although as noted in many places in the literature 
and emphasized in the writer’s previous paper, the ad- 
jacent rock may vary widely. In occasional instances 
in which the soil was found to be subacid in reaction and 
low in calcium compounds the plant is, as a rule, stunted 
and weak-looking. Its usual classification as a calcar- 
eous soil plant may thus be accepted, although it is evi- 
dently fairly tolerant of acidity. It is interesting to 
compare with Camptosorus the related fern Aspleniwm 
pinnatifidum. The latter grows usually on sandstone, 
shale, schist, etc., and has apparently never been defi- 
nitely reported on limestone or other calcareous rocks. 
A number of tests, made in Pennsylvania, Maryland, 
and Virginia, have shown its soils to contain some cal- 
cium compounds, but to be decidely acid in reaction. 
It is therefore to be classed as a typical acid soil plant, 
only slightly tolerant of calcium. The relations be- 
tween these two ferns will be further discussed later on. 
WasuHineton, D. C. 
(To be continued.) 
