in the cut mouths of the laticiferous vessels and it ceases to llow, 
although there may be much more in the liane, and if a cut liane 
is left the latex in the bark disappears little by little and when 
it is dead and dry the bark contains but a little rubber. The 
author’s theory to account for this is that the caoutchouc is not 
a secretion but the sap of the plant, and that it being employed 
by the cells as nutriment is used up and so disappears. This may 
well be doubted. However, the action of rapidly killing the cells, 
by simple heat or plunging the sections of the liane into boiling 
water has been found to kill the ceils and coagulate the latex in 
the bark. The pieces of the climber after being put into the boiling 
water, are then beaten with a club while still hot to detach the bark 
'which when dried by fire heat or exposure to a current of air, 
(never by sunheat) are broken up by beating and the rubber ex- 
tracted by mechanical means or solvents, sulphuric acid or potass. 
Only certain laticiferous barks yield to this process. It is a failure 
in the case of Para Rubber, Ceara Rubber and Chonemorpha Yer- 
sini. This latter climber appears to be very troublesome to work 
withv 
Tables of percentages of rubber obtained from three species of 
vines are given : 
From Ecdysanthera Lan&bitini , '373 of bark from the roots 
gave 7*45 per cent of Caoutchouc, -027 kilos in all, 4*466 
kilos of bark from the vine 6 cm. and more through gave 
7*64 per cent ’341 kilos of rubber. 
E. Annamensis gives a smaller proportion, 5*23 to 6*63 per 
cent. The highest percentage from the roots. 
Pezizicarpus montana gave a higher percentage, viz., 7*84 to 
8*30, but it appears to have a thinner bark, as a stem 13*50 
metres long and 5 cm. through only gave 2,000 kilos of 
bark as against *Ecdysa ithera annamensis which gave 
6*400 kilos of bark from a liane 13 metres long and 6 cm. 
through. 
The figures show a smaller result than those obtained from quite 
freshly collected barks, and it is clear that all treatment of bark 
should be carried out as soon as possible after collecting. 
Editor , 
A MEMORANDUM OF CASUARINA EQUI- 
SETIFULIA, ITS CULTIVATION 
AND TREATMENT, 
with Special Reference to the Planting of Abandoned 
Mining Land in the Federated* Malay States. 
Casuarina equisetifolia , Forst, Sun: C . muricata, Ruxb. FI. Ind* 
111, p. 519 — Order Casuartneee. 
