GIANT BAMBOOS. 
265 
4. The greatest growth actually recorded in 24 hours was 
46 cm. 
5. The daily rate of growth is strongly affected by 
external factors, among which the principal are rainfall and 
the psychrometric condition of the air. 
6. This effect appears to be greater the greater the height 
which the growing halm has reached. 
7. The greatest observed change in the rate of growth 
between two consecutive days amounted to 50 per cent, of 
the average rate of growth. 
8. Growth is almost always more rapid by night than by 
day, but on one exceptionally wet day a particular culm 
grew more rapidly than during the following night. 
9. The average hourly growth between 7 A.M. and 5 P.M. 
(day) was 6 mm., between 5 P.M. and 7 a.m. (night) 16 mm. 
at heights of 3-12 metres. 
10. The maximum rate of growth was reached soon after 
dark, but throughout the night growth was fairly constant. 
And with this is to be associated the fact that water was 
excreted from the tips of the sheathing leaves during the 
greater part of the night. 
11. The most rapid growth recorded at night was 23 mm. 
per hour. 
12. During some parts of the day a slight shrinkage was 
recorded on several occasions. This never amounted to 
more than 2 mm. per hour and was always preceded by 
one or more hours of sunshine. 
13. The curve of growth by day follows very closely 
that of the percentage moisture of the air. 
14. This effect is probably (to a large extent) due to the 
transpiration of the adult members of the clump. 
15. Any effect of the change from night to daylight or 
vice versa apart from psychometric changes was not great 
enough to be recognized by the methods employed. 
Peradeniya, March 25, 1904. 
