66 CA]\IPTOSORUS 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 — 



" In 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 it a 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 base 

 into obtuse auricles." When it is noticed, as in our plate, 

 how long and tapering are the terminations of the fronds, 



