Frof. Schouw on tlie Geographic Distribution qf Grasses ^ 
bread. The middle or the south of France, England, part of 
Scotland, a part of Germany, Hungary, the Crimea and Caucas- 
us, as also the lands of middle Asia, where agriculture is followed, 
belong to this zone. Here the vine is also found ; wine supplants 
the use of beer; and barley is consequently less raised. 
Next comes a district where wheat still abounds, but no ' 
longer exclusively furnishes bread ; rice and maize becoming fre- 
quent. To this zone belong Portugal, Spain, part of France on 
the Mediterranean, Italy and Greece ; further, the countries of 
the East, Persia, Northern India, Arabia, Egypt, Nubia, Bar- 
bary, and the Canary Islands : in these latter countries, however, 
the culture of maize or rice, towards the south, is always more 
considerable, and in some of them, several kinds of sorghum 
(Dura) and Poa Ahyssinica come to be added. In both these 
Tegions of wheat, rye only occurs at a considerable elevation ; 
oats, however, more seldom, and at last entirely disappear ; bar- 
ley affording food for horses and mules. 
In the eastern parts of the Temperate Zone of the Old Con- 
tinent, in China and Japan, our northern kinds of grain are very 
unfrequent ; and rice is found to predominate. The cause of 
this difference between the east and the west of the Old Conti- 
nent, appears to be in the manners and peculiarities of the peo- 
ple. In North America wheat and rye grow as in Europe, but 
more sparingly. Maize is more reared in the western than in the 
Old Continent, and rice predominates in the southern provinces 
-of the United States, 
In the Torrid Zone, maize predominates in America, rice in 
Asia, and both these grains in nearly equal quantity in Africa. 
The cause of this distribution is, without doubt^ historical ; for 
Asia is the native country of rice, and America of maize. In some 
situations, especially in the neighbourhood of the Tropics, wheat 
is also met with, but always subordinate to these other kinds of 
grain. Besides rice and maize, there are, in the Torrid Zone, se- 
veral kinds of grain, as well as other plants, which supply the 
inhabitants with food, either used along with them, or entirely 
occupying their place. Such are, in the New Continent, yams 
(Dioscorea alata), the manihot {Jatropha manihot), and the ba- 
tatas {Convolvulus hatatas')y the root of which, and the fruit of 
the pisang (Bananse, Musoe, sp.), furnish universal articles of 
