BOTANY OF SORGHUM. 61 



The above will suffice to settle a question, which could not have 

 arisen but that a recent writer, who, by some, might be assumed to 

 speak with authority, has in his writings confounded the sorghums 

 with sugar-cane, while he places a single variety of sorghum appa- 

 rently in a genus by itself. 



The Agricultural Character of Sorghum. 



Under this head the Committee of the National Academy of Sci- 

 ences say in their report : 



The cultivated varieties of soro;hura, considered botanically, are cereals. 

 The}- belong more especially to that very small group of cereal species which 

 have been cultivated from the dawn of history, and have developed along with 

 our civilization. During ages of culture they have so changed under the hand 

 of man, that we are ignorant as to their native countries, and know not what their 

 original wild progenitors were. Their descendants now exist in a vast number 

 of varieties, which differ so greatly among themselves, that neither scientific 

 botanists nor practical cultivators are agreed as to what are true species, and 

 what mere varieties which have arisen in cultivation. 



The cultivated varieties of sorghum have been placed in the genera IIolciis, 

 Andropogon, and Sorghum, by different botanists — the latter being the name 

 now accepted. 



A generation ago, botanists grouped the numerous cultivated varieties into 

 a considerable number of distinct species, without agreement as to how manj-: 

 five or six were generally believed to exist. Certain varieties of durra, with 

 the grain in a somewhat loose panicle, and which were more especially culti- 

 vated in Asia and in southern Europe, were classed as one species called »Soj'- 

 ghum {Uolcus or Andropogon) viilgare ; the varieties with the grain in a 

 densely contracted panicle, grown more largelj' in Africa, and known as Guinea 

 corn, Egyptian durra, Moorish millet, etc., were grouped into another species 

 called S. cernuum ; the variety best known as chocolate corn was the S. hicolor ; 

 broom corn, and all the sugar producing kinds, were classed together as (S. 

 saccharatnm ; and other specific names were applied to smaller groups of 

 these varieties. 



But the investigations of modern science have gradually led to the belief, 

 that all the numerous varieties once classed i;i the several species above enu- 

 merated had a common origin and constitute but a single species, to which the 

 old name Sorghum vuJgare is now applied. 



This is now the belief of the most eminent botanists of the world. Some 

 even go further, and believe that all the cultivated varieties of the genus, includ- 

 ing the spiked millets (Sorghum (Holcus) spicutum), are the descendants of a 

 single original parental species. 



These conclusions have a most important bearing upon the subject of this 

 special investigation. 



It is a law of nature, that the longer a species is cultivated and the wider its 

 cultivation extends, the more easily it changes into new varieties, and the wider 

 the differences between the varieties become. Some species, however, have a 



