CHAPTER IV 



THE PHYSIOLOGY OF LATEX (continued] 



TAPPING EXPERIMENTS 



Introductory. 



THE examination of the living latex vessels in situ 

 is a matter of extreme difficulty. On the other hand, 

 the removal of the bark from the tree is followed by 

 immediate collapse of the vessels, by the loss of a large 

 part of their contents and by marked changes in form. 

 Our knowledge of the physiology of the laticiferous 

 system is therefore almost entirely derived from a study 

 of the behaviour of the trees during the process of 

 tapping. Experiments in tapping Hevea brasiliensis 

 were carried out by the author at Henaratgoda, Ceylon, 

 during the years 1908 1912. These experiments were 

 begun in consultation with Dr J. C. Willis and Mr M. 

 Kelway Bamber, of whom the latter also collaborated in 

 the earlier experiments. 



Throughout these experiments a particular system of 

 tapping was adopted. This was done, not because the 

 system itself was regarded as an ideal one, but for the 

 sake of uniformity, in order that there should be a 



