POSSIBILITIES OF ECONOMIC BOTANY. 63 



nal uses shows how slender has sometimes "been the claim of cer- 

 tain plants to the possession of any real utility. But some of the 

 plants which have been brought to notice in these ways have 

 afterward been found to be utilizable in some fashion or other. 

 This is often seen in the cases of the plants which have been sug- 

 gested for medicinal use through the absurd doctrine of signa- 

 tures.* 



It seems clear that, except in modern times, useful j^lants have 

 been selected almost wholly by chance, and it may well be said 

 that a selection by accident is no selection at all. Nowadays the 

 new selections are based on analogy. One of the most striking 

 illustrations of the modern method is afforded by the utilization 

 of bamboo fiber for electric lamps. 



Some of the classes of useful plants must be passed by without 

 present discussion; others alluded to slightly; while still other 

 groups fairly representative of selection and improvement will be 

 more fully described. In this latter class would naturally come, 

 of course, the food-plants known as 



I. The Cereals. — Let us look first at these. 



The species of grasses which yield these seed-like fruits, or, as 

 we might call them for our purpose, seeds, are numerous ; f 

 twenty of them are cultivated largely in the Old World, but only 

 six of them are likely to be very familiar to you, namely, wheat, 

 rice, barley, oats, rye, and maize. The last of these is of Ameri- 

 can origin, despite doubts which have been cast upon it. It was 

 not known in the Old World until after the discovery of the New. 

 It has probably been very long in cultivation. The others all 

 belong to the Old World. Wheat and barley have been culti- 

 vated from the earliest times ; according to De Candolle, the chief 

 authority in these matters, about four thousand years. Later 

 came rye and oats, both of which have been known in cultivation 

 for at least two thousand years. Even the shorter of these pe- 

 riods gives time enough for wide variation, and, as is to be ex- 

 pected, there are numerous varieties of them all. For instance, 

 Vilmorin, in 1880, figured sixty-six varieties of wheat with plain- 

 ly distinguishable characters.J 



If the Chinese records are to be trusted, rice has been culti- 

 vated for a period much longer than that assigned by our history 

 and traditions to the other cereals, and the varieties are corre- 

 spondingly numerous. It is said that in Japan above three hun- 



* The Folk Lore of Plants. By T. F. Thiselton Dyer, 1889. 



f In Dr. Sturtevant's list, 88 species of Graminece are counted as food-plants under 

 cultivation, while the number of species in this order which can be or have been utilized 

 as food amounts to 146. Our smaller number 20 comprises only those which have been 

 grown on a large scale anywhere. 



X " In Agricultural Museum at Poppelsdorf 600 varieties are exhibited." 



