found in albumen. This substance is best
known as a constituent of animals, and it does not appear to be abundant
in plants. The portion of the gluten of wheat-flour, which is insoluble
in boiling alcohol, is considered by Liebig and Dumas to be coagulated
fibrin.

In the seeds of leguminous and a few other kinds of plants large
quantities of a substance termed _legumin_ are found. It resembles the
casein, or cheesy ingredient of milk; indeed, some chemists consider it
to be identical in composition with that substance. When pure, it is
pearly white, insoluble in boiling water, but soluble in cold water and
in vinegar. The saline matters found in plants are always associated
with the albuminous bodies; the latter, therefore, form the bones as
well as the muscles of animals.

A great many substances are found in plants, such as wax, mannite,
"extractive matter," citric, malic, and other acids, of the nutritive
value of which very little is known. The substances described in this
section constitute, however, at least 95 per cent. of the weight of the
vegetable matters used as food by live stock.

SECTION III.

GREEN FOOD.

_The Grasses._--More than one-half the area of Great Britain and Ireland
is under pasture; the grasses, therefore, constitute the most important
and abundant food used by live stock. The composition of the natural
and artificial grasses is greatly influenced by the nature of the soil
on which they are grown, and by the climatic conditions under which
they are developed. Many of them are almost worthless, whilst others
possess a high nutritive value. Amongst the most useful natural
grasses may be enumerated Italian rye-grass, Meadow barley, Annual
Meadow-grass, Crested dogstail-grass, Cocksfoot-grass, Timothy or
Meadow catstail-grass, and Sweet vernal-grass. Amongst grasses of medium
quality I may mention common Oatlike-grass, Meadow foxtail grass, Smooth
and rough stalked Meadow-grass, and Waterwhorl-grass. There are very
many grasses which are almost completely innutritious, and which ought,
under no circumstances, to be tolerated, although too often they make
up the great bulk of the herbage of badly-managed meadows and pastures.
Such grasses are, the Meadow soft-grass, Creeping soft-grass, False
brome-grass, and Upright brome-grass. The rough-stalked Meadow-grass,
though spoken favorably of by some farmers, is hardly worthy of
cultivation, and the same may be said of many of the grasses whic