478 
WRIGHT: FOLIAR PERIODICITY 
from a study of these some light may be thrown on the 
general trend of periodicity in plants which for ages past 
have been accustomed to the climate prevailing here. It is 
more than probable that investigations of the Indo-Malayan 
flora will prove that many of our species, now considered 
endemic, are distributed in areas outside Ceylon, but such 
discoveries will not seriously affect the considerations dealt 
with in this paper. Throughout this paper the names and 
distribution of the plants as given in Trimen’s Flora and the 
Peradeniya herbarium have been accepted as correct. 
The endemic species are remarkable for the scarcity of 
deciduous forms, about ninety-four per cent, of the 
arborescent species being typical evergreens. The natural 
orders Sapotaceæ, Dipterocarpaceæ, Ebenaceæ, and the 
genera Semecarpus, Eugenia, Memecylon, and Symplocos, 
contain a remarkable high percentage of endemic species 
which grow into huge trees, very few of which are deci¬ 
duous. The evergreen trees may produce a large quantity of 
new leaf once each year, some of them twice per year, but 
most of them are characterized by irregular leaf production 
during each month of the year. 
Deciduous endemics .—Trimen mentions that Phyllanthus 
cyanospermus, Muell. Arg. (vol. IV., p. 27), a rare species 
found in the wet districts of Ratnapura and Ambegamuwa, 
and Allæanthus zeylanicus, Thw. (vol. IV., p. 102), found in 
the Peradeniya and Maturata districts, are deciduous. The 
deciduous character of these species has been confirmed, and 
the following species can now be added to the list of Ceylon 
deciduous endemics :— 
Artocarpus nobilis, Thw. 
Canarium zeylanicum, Bl. 
Canthium macrocarpum, Thw. 
Holarrhena mitis, Br. 
Julostylis angustifolius, Thw. 
Pericopsis Mooniana, Thw. 
Sapindus erectus, Hiern. 
