﻿594 Gilbert : Revision of the Bermuda Ferns 



water collects in a rainy period, but which can always be traversed 

 on foot except for a sluice way, perhaps eight to ten feet broad, 

 which apparently has no current and no outlet, and which is often 

 completely covered with duckweed [Lemna minor). On the 

 margins of these dark sluggish waters grow large numbers of 



dog-bush {Baccharis heterophylla), while in the marshes themselves 

 grow the omnipresent juniper, occasional large specimens of the 

 palmetto (Sabal Palmetto), several species of Cyperaceous plants 

 and quantities of ferns belonging to five or six species only. 



There are two kinds of so-called " caves " in Bermuda. Sev- 

 eral of them are genuine caves, and there the ferns grow, not in- 

 side the caves, but on the rocks and debris about their entrances. 

 The other caves are simply holes in the earth, open to sun, air 

 and rain, sometimes twelve to fifteen feet across at the top and 

 as many feet deep ; sometimes 1 50 feet across and sixty to seventy- 

 five feet deep. Geologists say that all these were once genuine 

 caves, the roofs of which became too heavy to hold themselves 

 up and fell into the interior, carrying with them whatever vege- 

 tation had grown on the surface. Darwin, in his "Voyage of 

 a Naturalist," tells us that at the Galapagos Islands also " the tops 

 of caverns have fallen in, leaving circular pits with steep sides." 

 These caves are shady ; they retain moisture longer than the upper 

 surface ; they are protected from the severe winds ; and as a con- 

 sequence they are the haunts of the rarest and choicest ferns of the 

 islands. The descent into these cavities is always steep, sometimes 

 precipitous. They occur chiefly in what is known as " the Wals- 

 ingham tract," a peninsula lying between Harrington sound on the 

 west and Castle Harbor on the east, about three miles in length 

 and one to two miles in width. It takes its name from the former 

 residence of Tom Moore, the Irish poet, who was appointed to a 

 government office in Bermuda and lived there for about six months, 

 but was too fond of the gaieties of London life to remain longer. 



As 



111 



Bermuda, I propose to speak of each separately and of the locality 

 in which it grows. 



« 



Adiantum capillus-Veneris L. 



None of the authorities credit Bermuda with this species, but 

 it will certainly have to be included, although probably naturalized 



