218 



a library with reference books, literature on chemistry, tropical 

 agriculture, entomology, botany, coffee, and rubber, about forty 

 periodicals, and some 4,000 pamphlets on agricultural and related 

 subjects. 



Our first work was to take a survey of conditions on the 

 rubber plantation. Detailed observations were made of the rubber 

 over the entire estate. These data were copied on cards such as 

 intimated above. Maps were made shewing the condition of the 

 rubber on different areas and from different points of view. 

 Suggestions were made as to treatment of the rubber stand. A 

 drainage system was partly worked out. 30,000 trees were 

 measured to ascertain the average girth and height of trees of 

 various ages. Observations on branching, leaf-formation, root- 

 development and light requirements were made. A complete 

 working plan for 30 years was formulated and submitted to the 

 managing director. Insect and fungus diseases were studied and 

 remedies tried. Means for preventing forest fires in the rubber 

 were suggested. 



A number of well-developed young rubber trees were selected 

 in the field and transplanted to the experimental grounds, which 

 had been opened. Here seeds of different Castilla varieties have 

 been sown. Ceara and other rubber-producing trees and vines 

 have been planted. It is intended to get a complete collection of 

 the world's rubber and guttapercha plants. Castilla seeds have 

 been sown under varying conditions of soil to ascertain the differ- 

 ence in development. Manuring experiments have been com- 

 menced. Influence of catch crops is being studied. Observations 

 are made as to the best method of weeding, and the result of this 

 as shown in the progress of the rubber trees. Pruning and trans- 

 planting experiments are going on, as well as experiments in 

 grafting and hybridizing. 



In the course of the plant physiological work experiments on 

 transpiration have been commenced ; the temperature of the tree 

 and of the latex in the tree is ascertained under different weather 

 conditions; the effect of wounding is studied; root and bark 

 pressure is experimented upon ; relation of leaf-fall to latex is one 

 subject of investigation ; several other lines of inquiry have been 

 entered upon, and numerous new problems will be studied in the 

 future. 



The bacteriology of latex and crude rubber is not entirely 

 unknown, and we have ascertained some very interesting facts. 

 Before these are published, however, the flora of the crude rubber 

 is being classified by a specialist and the enzymes are carefully 

 i I) vestigated. We have tried over one hundred different chemicals 

 in regard to their disinfecting power, and we have no difficulty in 

 preserving the latex for a considerable time. By the addition of 

 formalin to the latex it can be kept for at least 27 months with- 

 out changing its character. This is the oldest latex I have had 

 to deal with, but I am inclined to believe that the latex can be 

 kept indefinitely. I have deposited in La Zacualpa laboratory 

 samples of latex, which are now 1 1 months old, and I put up a 



