THE ORIGIN OF ORGANIC MATTER 59 



marked reductions in per capita consumption of farm and forest products, 

 or make changes in both regards." 



It is at least highly probable that the relative increasing scarcity of 

 land resources will in a measure be met by increased production per acre 

 and readjustments of standards and habits of living. But if we accept 

 the conclusions of the foregoing report, it certainly appears highly im- 

 probable that any considerable area of land can be devoted to the produc- 

 tion of industrial energy. 



There remains in this connection one factor the value of which it is as 

 yet impossible to evaluate. This applies to the arid or desert regions. 

 There are about 468.000.000 acres of arid grazing land most of which 

 is of low productivity and about 67.000.000 acres of waste desert. It 

 is calculated that there are about 30,000,000 acres capable of irrigation. 

 But the greater portion of the arid lands will probably never be cultivated. 

 Most of these regions are subjected to solar radiation of high intensity 

 and have a large percentage of clear days. If science devises a means 

 of directly utilizing solar energy, may not these be the regions of greatest 

 value for such an undertaking? 



Recognizing the difficulties which beset the production of fuel through 

 the intermediarv of crop plants, the suggestion has repeatedly been made 

 that all that is necessary is that the botanist or horticulturalist create 

 some kind of a "super-plant." That is. while it is realized that present 

 crops are not adequate to supply the necessary amount of carbohydrate 

 or oil. it ought not to be difficult for the biologist to produce a plant 

 which instead of yielding 300 gallons of alcohol per acre would, for 

 instance, yield 3,000 gallons. This is. of course, the same question which 

 is constantly recurring in regard to the problem of food prodaction : why 

 does not the agricultural explorer bring in new plants which yield two 

 bushels in place of one ? The answer is the same for both cases, namely, 

 that the food-plants which constitute our chief means of subsistence were 

 already brought into cultivation by primitive man. While there is a 

 large yariety of plants which are used as food in one form or another, 

 man almost the world over, derives most of his food from the grass 

 family, the grains. These together with the seeds of some legumens and 

 oil-bearing nuts constitute the mainstay of man's existence. Undoubtedly 

 our standards of living will in time undergo some readjustments and 

 the yields per unit area be increased somewhat, but it is doubtful whether 

 these will more than keep step with the increasing demand for food 

 occasioned by a growing population. 



In advocating the production of material to replace our present sources 

 of energy by means of agriculture not only is the question of area an im- 

 portant one but a number of other factors immediately present themselves. 

 For the production of energy on a large scale reliance could not be placed 

 upon extant material. Recourse would have to be taken to very ex- 

 tensive cultivation. \\''hile, as has been stated, there is still considerable 

 arable land not yet under cultivation, it is very clear that any interfer- 



