FOKMATION OF NODULES. 
259 
Distribution. 
Nodules have been recorded’ from every country where 
plantations of Hevea hrasiliensis have been established ; they 
are found in Ceylon, the Federated Malay States, Singapore, 
Java, Sumatra, South India. One record (16) comes from 
Dutch Guiana ; this is noteworthy, as Dutch Guiana is on the 
reverse slope of the Amazon Valley watershed, and probably 
has Hevea indigenous to its flora. 
In a report (1) prepared for the Brazilian Government, 
Akers says of the Malay Peninsula : “ The worst pest brought 
to the notice of the Commissioners was the formation of burrs 
or nodules in the bark. While these do not materially affect 
the health of the tree, they are a serious interference to tapping. 
They occur principally on old trees that have been badly 
tapped in past years, but they are found also on trees that have 
never been tapped. Dr. Huber considers that they are the 
result of suppressed bud expansion combined with bad tapping, 
and this diagnosis is supported by Mr. Lewton Brain, the 
Director of Agriculture at Kuala Lumpur. Dr. Huber further 
thinks that they may be induced by the action of sun on 
renewed bark causing an irritation It is worthy of 
note that in the Amazon Valley, where the trees have been 
hacked about to a merciless extent by the use of the small axe 
(macJiadinho), these nodules are practically unknown.” 
It is interesting, in view of the statement contained in the 
last sentence, to read a report (2) on the Amazon Valley made 
by Akers for the Brazilian Government : “ The older trees are 
hacked about in disastrous fashion Naturally the 
trunks have become a mass of wooden warts with only a thin 
covering of bark.” Again, Akers says later : “ At every stroke 
of the axe the cambium is penetrated Moreover, 
these gashes in a very short time transform the trunk into a 
mass of knots and warts, half the size of a man’s fist, and over 
these only a thin covering of renewed bark is formed in the 
course of the next year or two.” 
As early as 1877 Hevea so deformed had been reported from 
Brazil. Cross in his report (9) to the India Office says : “ From 
the ground up to a height of 10 or 12 feet the trunk was one 
swollen mass of warty protuberances and knots covered with 
