70 AMERICAN FERN JOURNAL 
color, sometimes in a silky lustre, and is of great im- 
portance in helping to maintain a film of water over 
the surface of the frond, as well as in protecting it from 
danger of extreme desiccation. The climbing T. rad- 
icans (very close to T. boschianum of Florida) is the 
largest of the Jamaican filmy ferns, its fronds sometimes 
measuring 15 inches in length. In every feature of 
habit and appearance it is closely matched by T. scandens 
which is, however, so hairy as to be distinguishable 
from T. radicans at a distance of twenty feet. There 
are other cases of closely similar species, which differ 
chiefly in one being glabrous and the other hairy, as 
H. polyanthos and A. ciliatum. 
In the Jamaican series of ferns hairiness is much 
more common in Hymenophyllum than it is in Trich- 
omanes. All of the very hairy ferns are epiphytes, and 
without exception their fronds are limp and pendent. 
In H. sericeum the fronds continue to grow at the apex, 
while the oldest pinnae blacken and die. The golden 
brown and densely pubescent fronds of this form are 
a common sight in the rain-forest, hanging from moss- 
covered limbs (see plate 4). The hairy pendent species 
are found only in the very moist mountain forests above 
4000 feet. Common among them are H. lanatum, with 
small simply pinnate fronds, H. lineare, H. hirsutum, 
and T. lucens, a beautiful form in which the fronds 
are both hairy and crispate. The lower side of a lean- 
ing trunk may often be found with a uniform covering 
of H. lanatum or H. lineare, each frond pointing exactly 
downward, and often dry when everything else in the 
forest is wet. 
_ One of the most striking things about the filmy ferns 
is the ability of many of the species to grow as epiphytes 
more than half way from the ground to the canopy of 
of the forest, and in other relatively dry situations. 
In order to realize the difference between the environ- 
