264 
LOCK : THE GROWTH OF 
further observations upon tropical plants of other orders 
may lead to results of equal interest. Hitherto practically 
all the generalizations of plant physiology have been based 
upon experiments carried out with plants native to the 
temperate zone. An extension of such experiments to the 
tropics is highly desirable and the work is so far almost 
untouched. 
The effect of changes of moisture upon the normal growth 
of plants has been very little attended to even in temperate 
climates, so that there seems to be still considerable scope 
for experiments in this direction. And the examination of 
a considerable number of plants belonging to as many 
different natural orders as possible is especially to be 
advocated from this point of view. 
Finally I desire to express my thanks to Mr. F. Darwin 
and to Mr. J. C. Willis, Director of the Peradeniya Gardens, 
who have aided me during my work both by encourage¬ 
ment and advice. To the latter I am especially indebted 
for many valuable suggestions. 
SUMMARY OF RESULTS. 
These are based upon observations of the growth of culms 
arising from large (full grown) clumps of Dendrocalamus 
giganteus. 
1. The culms show a gradually increasing rate of growth 
up to a height of approximately 5 metres. Afterwards 
growth remains nearly constant up to about 15 metres and 
then slowly falls off until the final height of 30 or more 
metres has been reached. 
2. The greatest observed length of the whole growing 
region was from 5-6 metres. 
3. The average daily rate of growth agrees closely with 
that in Java ; at a height of 1 metre it is approximately 
10 cm. per day, at heights from 5-15 metres 30 cm,, and at 
20-25 metres 15 cm. in 24 hours. 
