424 
WRIGHT : FOLIAR PERIODICITY 
account of the forests in various parts of Ceylon— a tropical 
island where a definite climatic periodicity prevails—is now 
given. 
Selecting as our first locality the forests of the Peak 
Wilderness, Singhe Raja, and Hinidum, where the rainfall 
varies from 100 to over 200 inches each year and the force of 
the north-east and south-west monsoons is experienced, we 
find that we are surrounded with some of the largest trees 
and most magnificent forest in the whole of the island. It 
is here that the species of Diospyros (ebony) reach their 
maximum dimensions, and where the huge trees of species 
of Doona, Dipterocarpus, Yatica, Garcinia, Canarium, Calo- 
phyllum, Chrysophyllum, Palaquium, and Bassia abound. 
I have visited these forests on many occasions and have been 
principally struck with the absence of any fixed period of 
the year when the plants undergo their change of leaf. 
Were it not for the occasional fall of leaf, or leafless condition 
of scattered trees of Dipterocarpus zeylanicus, Canarium 
zeylanicum,Bassialongifolia, and Trema orientalis,one might 
imagine that he was in the original “Regenwälder” so 
forcibly depicted by Schimper and Haberlandt. Each species 
seems to be acting on its own initiative, and its occupation on 
sloping hillsides, along river banks, or on flat areas does not 
appear to influence the phases of leaf-fail and production in 
the least. And even during the time of relative drought 
there is only a slight increase in the number of species which 
pass through their phase of defoliation, many effecting a 
change of leaf without ever being leafless—a phenomenon 
noticed by Warming in the forests of Minas-Geraes in Brazil— 
others remaining leafless for a few days and others for 
several weeks or months. 
If one passes to a district where the temperature is much 
higher and the rainfall only 50 inches or less each year, as 
in the forests of the Northern Province, the same facts 
respecting foliar activity present themselves. In some of 
these forests one may meet with colossal trees of Mimusops 
hexandra, Chloroxylon Swietenia, Diospyros Embryopteris, 
