PEsSIN: EPIPHYLLOUS PLANTS OF JAMAICA 11 
The scattered seeds germinate on the trunk, branches, or leaves 
of a tree or shrub and, with adequate moisture and other nutritive 
material, develop into epiphytes. He divides the fruits and seeds 
of epiphytes into three categories: first, those transported by 
birds, monkeys and other tree-inhabiting animals; second, those 
which are very light and may be transported by the wind and 
which may readily catch in the crevices of the bark and germinate 
there; third, those seeds which are especially adapted to be carried 
by the wind. Such seeds usually possess either hairs or wings or 
inflated coats which aid their distribution. 
It is conceivable that a great many of the epiphyllous forms 
here being considered arise from spores, for spores have been found 
on many leaves. The epiphyllous liverworts evidently arise 
often from gemmae, for many such gemmae in the process of 
development have been found on leaves. The spores of liverworts, 
on the contrary, have rarely been found germinating on leaves. 
The observations thus far made indicate that many an epiphyllous 
hepatic or moss makes its start on the host by creeping up the 
stem of the support from the ground or up the petiole from the 
stem. As it climbs upward it dies off from below and when its 
younger part reaches the leaves it spreads over the surface and 
becomes strictly an epiphyllous form. Secondly, epiphyllous 
forms may be lodged upon the host by the agency of water. 
When during a rain the water flows down over the leaves and 
branches of a tree in the rain forest, it breaks off the hepatics and 
mosses and other plants from the surface of the stem or leaf and 
washes them down on the leaves below, where they continue to 
grow, covering the leaf in the course of time with a dense mat. 
Such is probably the explanation of the fact that in most cases 
the lower leaves possess the greatest number of epiphyllous plants, 
though, of course, lower leaves are older, better shaded, and are 
surrounded by moist air. It is probable also that the epiphyllous 
plants found on the dorsal sides of certain overturned leaves arise 
in the manner just described. The fact that no epiphyllous 
plants were observed on the lower sides of leaves still in normal 
position is evidence that these plants are propagated largely by 
these fragments. If it were commonly by spores we should 
expect these, at least occasionally, to stick to the underside of a 
