PESSIN: EPIPHYLLOUS PLANTS OF JAMAICA 9 
On Taste I, E and F, are indicated the epiphyllous plants 
observed on the Blue Mountain Peak and in the Clyde River 
Valley. In the former, though there is always an abundance of 
moisture, the epiphyllous flora is not a rich one, owing probably 
to the frequent heavy rains, the rather low temperature and the 
occasional strong winds. Those of the Clyde River Valley occur 
chiefly on trees growing along streams, where there is sufficient 
shade and a humid atmosphere. 
iii E 
i. Part of transverse section of a leaf of Elaphoglossum latifolium (EF) 
a sa rhizoids (Rh) of an epiphyllous liverwort (L!) pressed into its cuticle. This 
liverwort in turn bears another epiphyllous liverwort (L*), which is likewise attached 
by its rhizoids (RA) 
In general, observations in these Blue Mountains of Jamaica 
show that the epiphyllous members of each group of plants are 
limited to certain regions where climatic conditions are suitable 
for such growth. Thus, Algae, Hepaticae, and Musci usually 
thrive best on the windward side of the mountains and are abun- 
dant only in very damp and very shady woods. Epiphyllous 
lichens, on the other hand, do not require very warm, humid, and 
shady places but are also found in relatively dry regions. It was 
rather difficult to ascertain with any degree of definiteness the 
exact age of the leaves which bore epiphyllous plants, but it is 
safe to state that none are present on very young leaves. As a 
rule they do not appear on leaves until the latter are one or two 
seasons old. : 
In order to determine the relation between the epiphyllous 
forms and the plants on which they grow, cross sections were 
made of the leaves of Elaphoglossum latifolium, Clusia havetioides, 
