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in the Levant, and cooked in the same manner as rice. ‘Four 
other sub-species not grown in England are Z’riticwm Polonicum, 
called Polish wheat, although probably of African origin ; 
Triticum amyllewm, starch wheat; and T'ritecwm monococcum, 
one grained wheat. 
The sub-species of oats (Avena) cultivated for grain are four in 
number, of which the most variable is the common oat (Avena 
_ sativa), some fifty varieties of which are grown in Britain, most 
productively in the northern or more elevated parts. The others 
are the Tartarian oat (Avena orrentalis) ; the short oat (Avena 
brevis), grown almost exclusively in the most mountainous 
districts of France and Spain ; and the naked oat (Avena nuda ). 
Barley, besides being probably the oldest, is the most widely 
cultivated of the cereals, its tillage extending from the tropics 
to northern Norway and Siberia, accompanied in boreal extension 
by the oat, which, however, does not reach quite so far north. 
In the extreme northern county of Scotland the eastern coast is 
richly manured with the abundant offal of the herring fishery, 
and there where wheat will not ripen, luxuriant crops of barley 
are grown, nearly altogether utilized in the production of the cup 
that cheers, but also inebriates, the Caledonian Celt, and the 
Circean charms of which his southern compatriots are not always 
able to resist. Barley may be divided into four sub-species— 
Hordewm vulgare, four-rowed ; Hordewm heaxastichon, six-rowed ; 
Hordeum zeocitron, fan or battledore; and Hordeum distichon, 
two-rowed or long-eared barley. 
Rye (Secale cercale) was once extensively cultivated in Britain 
as a bread corn. It is, however, now almost discarded here, but 
on the continent, especially in those parts of Russia and the 
adjacent countries which are unsuited for growing wheat, it still 
furnishes almost the only bread eaten by the inhabitants, and 
which, though less nutritious than that made from wheat, is 
found to keep longer. It is also employed as a substitute for 
coffee. 
The tracts in the northern hemisphere in which the four 
cereals under consideration can be grown have irregular 
boundaries, modified by local conditions, ike the thermal zones. 
North of the breadline, as Schouw terms it, lie the polar countries, 
where dried fish takes the place of bread. 
The highest of the cereal zones in Europe is, as has been 
already indicated, that of barley and oats, which extend from 
