1910] The Ottawa Naturalist. 87 



ing short of jubilant when I ended the season with 30 species; 

 this number rose in 1907 to 34 and in 1909 to 3 7. 



Ferns have a great Hking for Hmestone, and almost my 

 first expedition was to a creek flowing from Bass Lake to the 

 Lower Rideau. Its course is little more than a mile long, first 

 through beaver-meadows and then through pastures, where the 

 stream is shaded with trees and flanked on one side by limestone 

 cliffs ranging from 2 or 3 to 20 feet in height. Refreshing myself 

 at a natural well in the rock on the near bank of the stream, I 

 stepped across, scrambled up the loose talus and examined the 

 shaded wall of limestone above. If you are not a fern lover you 

 cannot share my feelings when I tell you I was standing within 

 arm's length of 3 new species. 



On the upper side of the topmost ledge stood a dense mass 

 of Polypody, forming a natural coping-stone, as it were, to the 

 rock wall. Beneath some lower ledges and in the horizontal 

 seams were tufts of Black Spleenwort {Asplenium Trichonianes) ; 

 while further in the shade, beneath some cedars that grew above 

 the rock and behind two maples that grew up from below was a 

 mass of tangled leaves what could they be? some sort of dock? 

 no! there were lines of spore-cases on the under side; it was the 

 Walking Leaf {Camptosorus rhizophyllus), and, as though to put 

 itself beyond suspicion or a doubt, it was actually walking; I got 

 a plant three of whose fronds had regained the moss on the face 

 of the cliff", rooted and given rise to plants of their own. 



The Walking Leaf must have shade. It is fond of limestone, 

 but in deeply-shaded damp woods I have found it growing on 

 sandstone, and if vou slash the woods and mutilate its svlvan 

 bowers, letting in, the sunlight, it will soon disappear even from 

 its favorite limestone shelves. Its foliage has not the glossy 

 finish of its congener, the Hart's Tongue, but its quaint growth 

 and a certain local rarity about it will always attract attention. 



The tendency of the long tapering frond with its sensitive 

 tip to regain the mossy bed from which it sprang, seems like an 

 instinct closely analogous to the blind groping movements of 

 certain lower forms of marine life; true the tentacle thrust forth 

 by the plant to search for the wall of its sea-cave swims in a 

 more impalpable elem.ent, the ocean of air, but it serves the same 

 purpose. The act is doubtless not a conscious one in either case, 

 but in both alike sensation is involved. Not seldom when the 

 frond has reached outwards to a distance from the rock and takes 

 a long time to return, the auricles at the base of the frond are 

 found stretching out blind hands in the shape of similar sensitive 

 tentacles. The great blocks of limestone that fill the Niagara 

 gorge are often densely carpeted with the Walking Leaf, the 



