32 
which will form the subject of papers and discussion 
at our meetings, and to which I shall be able only very 
briefly to allude in this address. 
An immense impetus has been given to the cultivation 
of rubber, chiefly through the largely increased demand 
which has arisen for rubber tyres owing to the per- 
fection and general use of motor vehicles. The in- 
creased demand occurred at a time when but few of 
the larger rubber plantations in the East had come 
into full bearing. A rapid and unprecedented rise in 
the market price of the raw material took place, and 
as a result new plantations were initiated in every 
country, especially in Asia and Africa, in which 
rubber can be grown, as well as in some places 
where the chances of success were very small. During 
this period rubber trees of every description were 
grown in plantations on a large scale, of which 
Hevea, Ceara and Castilloa are the most important. 
A struggle has since been in progress from which 
we are now beginning to emerge. There has been 
not only competition between the rubber of these 
plantations and the rubber derived from the forests of 
South and Central America and Africa, the result of 
which mainly turns on cost of production, but there 
has also been competition between the rubber of planta- 
tions of Hevea, of Ceara and of Castilloa, the result of 
which turns not only on cost of production, but also 
on the yield and quality of the crude rubbers furnished 
by these different trees. Certain conclusions are already 
definitely indicated. One is that the high reputation of 
the Hevea tree as a rubber producer in countries in 
which natural conditions are favourable to its growth 
is established beyond all question. Ceara and Castilloa 
trees, however, undoubtedly have possibilities in other 
countries, the climate and soil of which are unsuitable 
for Hevea brasiliensis. The production of rubber from 
Castilloa trees in plantations is confronted with special 
problems which are to be discussed at one of our 
meetings. 
It is, moreover, established that under existing con- 
ditions rubber from Hevea plantations can be produced 
at a smaller cost than the same rubber collected from 
forest trees in the Amazon region of South America. 
