basis for further generalizations, or, if a farmer, he may derive many 

 suggestions, hints, and rules by which to improve his methods. 



Very few appreciate the extensive range of edible plants, but the 

 lists given by E. L. Sturtevant (Agr. Sci., Vol. III., p. 174) suggest 

 that we have in the botanical world an almost unexplored field from 

 which to recover for the use of civilized man an endless variety of 

 foods and fruits unknown to our present cuisine and table. Sturte- 

 vant enumerates in detail the 210 natural orders of plants recognized 

 i)y botanists from the days of Linn?eus to those of Bentham and 

 ] looker. These orders include 8,849 genera and 110,GG3 species, and 

 Sturtevant shows that the edible plants include only 4,283 species, 

 repr(>senting 170 of these orders, so that only about 3^ per cent of the 

 known species of plants are now being used as food — most of them, 

 of course, to a very slight extent, only as auxiliaries to the princij^al 

 foods. 



The food plants extensively cultivated by man include only 1,070 

 species; that is to say, less than 1 per cent of all known species are 

 cultivated anywhere throughout the known world, and those actually 

 in ordinary use in European and American kitchen gardens represent 

 only 211 species. The preceding numbers all refer to the phenogams, 

 but Sturtevant gives supplementary lists covering the lower order of 

 plants. 



Therefore it would seem that the present condition of agriculture 

 and the present extent of our available vegetable foods is limited not 

 so much by our climate and soil as by our ignorance of the laws of 

 nature affecting plant life. We may not control the clinuite, but we 

 may rear natural plants and adopt rational methods of modifying 

 them by cultivation until they and we become quite independent of 

 the vicissitudes of drought and frost. 



In conclusion I gratefully acknowledge the enthusiastic assistance 

 that I have received from Mrs. R. S. Hotze as translator, and Mr. 

 E. R. Miller in the preparation of the index. 



