^MITH : APPLICATION OF THE THEORY OF 



therefore that it is only during the night that we can look for 

 such conditions as will allow of an adequate supply of water to 

 t he young culms. Only then are we likely to get the supply 

 of water in excess so as to bring in the temperature as the 

 limiting factor. 



The growing bamboo culms usually exude drops of water 

 (often copiously) from the tips and axils of the sheathing 

 bracts during the night, and it may be safely supposed that 

 when this occurs the supply of moisture is in excess of the 

 requirements for growth at that temperature. This exudation 

 usually begins at Hakgala as soon as darkness sets in and 

 continues through the night, so that for about eleven hours of 

 darkness we have conditions in which the temperature may 

 be supposed to be the limiting factor, and a falling curve of 

 growth is usually observed. 



At Peradeniya the atmosphere is not by any means so usual- 

 ly at or near saturation during the night, and the exudation 

 of drops of water varies considerably with the state of the 

 atmosphere. Sometimes the exudation of water begins early 

 in the night, sometimes it is postponed till later. The time 

 when the exudation begins also varies with the height of the 

 culms, the taller culms always being later than the short 

 ones. 



On the night of July 6th to 7th, represented in the curve on 

 Plate 24, the exudation was not taking place in all 5 culms until 

 11 p.m. The important point to notice here is that after 

 this lime we should expect on our theory that the growth 

 tld<be limited l>y the temperature. It will be seen however 

 that the temperature after this time varied so little that it 

 OOUld scarcely be reflected in the curve of growth. 



The growth ourve alter this time presents at least as much 



mblanoe to the curve of temperature as to the curve of 



humidity, hut the circumstances are not such as to present a 



deci Me as to which is the controlling factor during the 



i time that we have olear evidence of the supply of watei 



being in e: 



