While a significant number of scientists are assessing the future of renewable and nonrenewable sources of energy, and their potential use­fulness and costs, a few of them are busy exploring existing storehouses of nature and modifying the renewable resources into direct conventional fuels. Prof. Melvin Calvin and his group at the University of California at Berkeley emphasize the importance of a group of plants which, in addi­tion to producing polysaccharide, also produce polyisoprenes (rubber) and similar associated products [4]. While the Hevea produces rubber, different euphorbiacea produce polyhydrocarbons that have molecular weights lower than 10% of that of average natural rubber. It is likely that chemical manipulation may yield liquid fuels similar to that of conventional gasoline or diesel out of these products.

The interesting aspect of these plants is that rubber plants demand good insolation and high moisture content in soil as well as in the atmos­phere. But many subspecies of Euphorbia can grow comfortably in sunny semiarid lands, where standard cultivations are not economically viable [5]. This leads us to two major considerations: (1) soil conservation, eco­logic improvement, and increase in P/R (productivity/respiratory) ratio; (2) production of hydrocarbon and biomass, both of which have energy value.

Avalois is the North Brazil variety, and Euphorbia tirucalli is the Southern Californian equivalent of the plant. Both of them usually con­tain 30% hydrocarbon in their latex. Similar or parallel plants in the Indian Subcontinent are not yet well known. But like rubber plantation, which successfully migrated from Brazil to Malaysia, one may try a few

species of Euphorbia—particularly on the rocky, arid, or laterite belts, which are rather unproductive for forestry or cultivation. It is worth­while to take a glance at some information already available on these products [6].