420 



and advising measures for its prevention. It is viewed 

 with alarm by many planters, but if the directions I have 

 laid down for its treatment are followed, it will ultimately 

 be stamped out. In fact I believe that its method of in- 

 fection combined with the energy which most planters are 

 exhibiting in grappling with it, if strenuously continued, 

 will ensure its disappearance from all plantations before 

 the trees are four years old. 



Excrescences on Bark. — On old Para trees three types 

 of excrescence make their appearance on the lower four or 

 five feet of the stem: 



Firstly, small nodules, usually called "peas," because 

 they are generally first noticed when they are such a size, 

 and found on trees of three years and older, both tapped 

 and untapped . They have a sharp fang-like 1 ' root, ' 1 which 

 comes from the wood through the cambium. The "peas" 

 are easily knocked out with a chisel or the back of a knife, 

 and the wound soon heals over. Most planters have special 

 coolies detailed off to remove these excrescences. 



Secondly, large outgrowths of all sizes up to four or 

 five feet long, a couple of feet wide, and of various thickness 

 up to six inches, occur on tapped trees and on tapped areas. 

 These can usually be prized back, and break off, exhibiting 

 a "root" of a few square inches, and continuous with the 

 wood of the tree. They look like much malformed branches 

 and may arise from dormant or from adventitious buds. 

 Some planters say they are due to bad tapping. Numbers 

 of the nodules already mentioned often occur on these out- 

 growths. As they grow over the original bark and cam- 

 hiuni, they are amenable to treatment. If broken off, the 

 true cambium soon regenerates a new bark, and only the 

 "root" remains uncovered, and this heals over in time. I 

 always advise covering the "root" with tar. There are 

 many indications that these larger growths are the "peas" 

 which were not excised. 



Thirdly, a less •common form appears as a swelling 

 of the stem of the tree and cannot be removed like the 

 others. 



My investigations have not succeeded in associating a 

 living organism, insect, bacterium or fungus with these out- 

 growths. It seems not improbable that the third form, at 

 any rate, is due to some derangement of the internal econo- 

 my of the tree. Many of the individual cells of the swelling 

 are much beyond the ordinary size, and frequently an ex- 

 cessive flow of latex occurs round the edges of the out- 

 growths. 



