32 
probably of use in this way to many smaller ferns. Cartilaginous bor- 
ders, if sharp or deflexed, also help to keep the nether surface dry. Their 
greatest development in Philippine ferns is in Elaphoglossury. 
Removal of water. -r- The ready removal of water from the frond is 
insured and facilitated in a variety of ways. One of these is by a smooth, 
even, waxy, unwettable surface, as in Asplenium musaefolium (the cuticle 
of which is firm enough to be stripped off), A. Phyllitidis, and Pteris 
op.aca. 
Caudate tips are a very familiar structure serving this end and, of 
course, acuminate tips in general are more common and less conspicuous 
structures of the same kind. Among conspicuously caudate tips are 
those of Oleandra colubrina, Coniogramme fraxinea, C. serrulata, 2 cen- 
timeters long, Asplenium musaefolium, A. Phyllitidis, Antrophyum lati- 
folium, A. semicostatum and Polypodium papillosum. Long-acuminate, 
rather than caudate, are those of Dipteris, Nephrolepis laurifolia , Asple- 
nium vulcanicum, A. caudatum, A. affine (the pinnse), Scolopendrium 
schizocarpum, Stenochlaena, Blechnum egregium, Antrophyum planta- 
gineum, Prosaptia, Polypodium subauriculatum, P. Zippelii, P. incur- 
vatum, P. Phymatodes and all its relatives, Drynaria and all its relatives, 
Lomagramma and Cheiropleuria. Very nearly all of these are epiphytes. 
The removal of water from an erect fern is brought about in the same 
way by an attenuate base, like that of Dipteris, Syngramma, Meniscium, 
Polypodium sinuosum and Cheiropleuria. Essentially like these are 
plants such as Odontosoria with cuneate, ereot pinnules. Pinnse drawn 
down at the base, instead of attached horizontally will drain in the same 
way; illustrations are Lindsaya Havicei and Asplenium caudatum and 
other species. The reduction of the basiscopic half of the pinna has 
the same effect, the part of the lamina which is removed being that 
portion which could not readily drain down the rachis ; this modification 
is begun in Asplenium vulcanicum ; carried farther in A. tenerum and its 
relatives and in Polystichum; farther still in Asplenium resectum; and 
completed in our dimidiate Lindsay as and Adiantum. 
If detracted pinnse are carried farther they become decurrent, forming 
a wing on the rachis and stipe which serves at once as a drain for water 
and mechanically, aside from any value it may have in increasing the 
leaf-area. Microlepia pinnata and Callipteris esculenta show slightly 
decurrent pinnse. Winged rachises and stipes are exceedingly common ; 
they are illustrated by Aspidium decurrens, Stenosemia pinnata (upper 
part), Davallia decurrens, Diplazium Wiluamsi, Scliizostege pachysora, 
Polypodium dolichopterum, P. affine, P. Schneideri, and Lecanopteris. 
A broad wing is sometimes convex upward on both sides, effecting & 
depression along the axis, as in P. papillosum, P. Schneideri and P. 
heracleum, the pinnse .of Pteris longifolia and the whole frond of Poly- 
podium caudiforme. The fine divisions of Onychium are concave above. 
