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WRIGHT : FOLIAR PERIODICITY 
unaccompanied by a heavy leaf-fail ; the periodicity of this 
tree was changed for a couple of years. 
Another case of interest has been observed for several years, 
where the flying foxes regularly visit certain trees of 
Bombax malabaricum along the riverside of the Botanic 
Garden and devour the whole of the leaves, and thus lead to 
the production of two sets of foliage each year. A similar 
defoliation is effected on trees of Portlandia grandiflora by 
some insect pest and a second crop of leaves is produced 
each year, though the trees do not appear to be able to stand 
such waste for many years more. 
3.—The Climate in Ceylon. 
It is necessary when dealing with plant phenomena which 
are influenced by external and internal forces to fully 
understand the variation in rainfall, air-temperature, and 
humidity at the different places where observations have 
been made. Most of the facts recorded in this paper have 
been obtained at Peradeniya and Hakgala, a few in the low- 
country between Henaratgoda and Colombo, others in the 
dry Northern Province between Anuradhapura, Yavuniya, 
and Mannar, and the remainder in the Badulla and Passara 
Districts of the Province of Uva. 
The rainfall in various parts of Ceylon is associated with 
definite monsoon periods, and the amount of rain accom¬ 
panying each varies considerably at different places. 
The south-west monsoon, according to the Government 
Meteorologist, usually lasts from February to July, and the 
north-east monsoon from August to January. 
It is necessary to consider each district separately, though 
they all agree in having rain every month in the year, a 
high temperature, and an atmosphere which is comparatively 
moist, the average humidity rarely being below 70 degrees. 
The Climate at Peradeniya. 
At Peradeniya the south-west rains are heavy during 
April and June, and those of the north-east still heavier in 
