490 Canadian Record of Science. 



various records, and have for three years past carefully 

 examined the present distribution of Montreal ferns, to 

 observe how far their distribution corresponded to the 

 past records. I hoped by these means to be able to trace 

 the influence of civilization in exterminating species 

 through the clearing of land and draining of wet places. 

 The change in the flora should be especially evident in the 

 case of the ferns on account of their peculiar habitat, and, 

 moreover, of no other group of plants have we such a com- 

 plete local record. The chief result of my investigation, 

 however, is a realization of the difficulty of exterminating 

 species even in a limited locality. Thus, out of the thirty- 

 two varieties recorded, I have been able to discover 

 twenty-nine still occurring, though several of these were 

 spoken of thirty years ago as on the point of disappearing. 

 Doubtless this persistent survival of species, which have 

 become rare, is partly due to the mountain having been 

 preserved as a park, though great changes have been 

 made in it. The following instances will serve to illus- 

 trate what I have stated : — 



Pellcea gracilis is only recorded from Montreal by Dr. 

 Holmes in 1822. In view of the very complete character 

 of several of the above records, the absence of any 

 mention of it since that time is sufficient proof of its 

 rarity. However, it still occurs sparingly on the mountain 

 side. 



Asplenium angustifolium is recorded by McCord and 

 Goode as occurring on the smaller mountain with 

 Aspidium, Goldianum, and a colony of this fern is still 

 found there, though A. Goldianum has probably become 

 extinct. 



Aspidium acrostichoides is recorded by Goode in 1879 as 

 occurring back of Sir Hugh Allan's and behind the 

 cemeteries, but becoming scarce. It is still found, how- 

 ever, in sufficient abundance in both localities. 



