Before considering certain general points arising out of the study of cereals, we have to discuss two other important crop plants—Rice and Maize—as well as a few minor members of the Gramineae, whose seeds supply food for man. Rice, Oryza sativa L. (Fig. 14), is probably the staple food of more people in the world than any other cereal. It is essentially a swamp plant, and the ‘deep-water Rices’ will succeed in 5 or 6 ft. of water. Certain varieties called ‘mountain Rices’, may, however, be cultivated with no more water than other cereals. The distribution of Oryza, like that of other aquatic plants, is very wide. At the present day it is apparently native to India, Australia and Africa, and it thus becomes very difficult to decide what was its country of origin. The earliest record we have of it is in old Chinese writings, and it has been cultivated continuously in that country since the remote past. Indeed there are fields in China where Rice is believed to have been grown for four thousand years uninterruptedly—a state of things rendered possible by the high pitch to which the use of manures has been brought in that country. The traditional Chinese ceremonies associated with the sowing of the five kinds of ‘corn’ at the vernal equinox, have a history stretching back into antiquity. The first spring sowing is attributed to the Emperor Shên-nung, the Father of Agriculture and Medicine, who reigned about 2700 b.c.