vi PREFACE 



developments are to be anticipated both in our scientific 

 knowledge of the physiological processes underlying the 

 formation of latex, and in the practical methods of 

 exploiting this most valuable of raw materials. It is 

 partly owing to our want of knowledge that it is still 

 possible to compress into a comparatively small compass 

 a summary of what is accurately known of both branches 

 of the subject. 



The chapters on the physiology of latex are largely 

 the outcome of original observations by the writer, 

 whilst those on planting, harvesting and factory work 

 on the estate are based on a close personal acquaintance 

 with the industry in Ceylon. The chapter on disease, 

 on the other hand, so far as it relates to the fungus 

 pests of rubber, is little more than a summary of the 

 work of Mr T. Fetch, whose book is indispensable to 

 anyone specially interested in this branch of the subject. 

 I am also indebted to Mr Fetch for the loan of the 

 illustration of canker on Hevea. Free use has also 

 been made of Mr Herbert Wright's well-known book 

 on Para Rubber, and the student who wishes to enter 

 further into the statistics of rubber cultivation will find 

 therein a large mass of useful information. 



Sir Daniel Morris's Cantor Lectures, delivered in 1898, 

 still contain the best and fullest account of the wild 

 sources of rubber, and I have drawn freely upon them 

 for the information given in Chapter n. 



