66 CAMPTOSORUS RHIZOPHYLLUS. — WALKING-LEAF, 
woods that our plant is found in Pennsylvania; and in other 
states some similar situation is usually its home. The specimen 
for our illustration was gathered near Philadelphia, along the 
Wissahickon 
«Tn the green valley, where the silver brook, 
From its full laver, pours the white cascade ; 
And, bubbling low amid the tangled woods, 
Slips down through moss-grown stones with endless laughter; ” 
and where, if Longfellow had taken this pretty picture from the 
very spot, he might have noticed the Walking-leaf on the moss- 
grown stones among which here at least it loves to grow. 
There has been much controversy as to the kind of rock on 
which the plant is found growing, some writers having claimed 
for limestone the sole privilege of finding ita home. But great 
numbers of observers have since recorded locations on sandstone 
rock; and the specimen we illustrate was taken from gneiss, a 
variety of granite rock, on the western side of the Wissahickon 
before referred to. That it was well satisfied with its location is 
seen by its picture, which is a fair average of its condition as 
found anywhere. It is however a very variable fern. Many 
collectors have found specimens with double fronds, one of the 
auricles or ear-like lobes at the base having grown out to 
almost the extent of the main blade, and rooting at the ends like 
its parent, or, as in such cases one might almost say, sister frond. 
Where our specimen was found one frond was gathered which 
had both auricles developed into fronds, not as. long as the 
central one, all three rooting at the ends, and having a remark- 
ably trifid character. Then while there are these variations 
in the line of division, there are often found tendencies in the 
opposite direction, that is to say, to be entire leaved. 
Mr. E. A. Rau, of Bethlehem, Pennsylvania, contributes to 
the first volume of “ The Botanical Gazette” an account of many 
varying forms, among others “some bearing sori, in which the 
frond is remarkably short, oblong, obtuse, widening at the basé 
into obtuse auricles.” When it is noticed, as in our plate, 
how long and tapering are the terminations of the fronds, 
