in the cut mouths of the laticiferous vessels and it ceases to Mow, 

 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 th2 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 lire heat or exposure to a curre nt of air, 

 (never by sunheat) are broken up by beating and the r ibber 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 

 with. 



Tables of percentages of rubber obtained from three species of 

 vines are given : 



From Ecdysantlicra Langbiani\ '373 kilos 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. Annamcnsis gives a smaller proportion, 5*23 to 6*63 per 

 cent. The highest percentage from the roots. 



Pezizicarpns 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 Ecdysaithera annamcnsis 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 EQJJI- 

 SETIPOLIA, ITS CULTIVATION 

 AND TREATMENT, 



with Special Reference to the Planting of Abandoned 

 Mining Land in the Federated Malay States. 



Casuarina equisctifol'uu Forst., Sun: C. muricata, Roxb. Fl. Ind* 

 III, p. 519 — Order Casuarincr. 



