nd mammoth varieties are biennial, but sometimes they assume
the perennial quality. Sweet clover is biennial. The crimson, Japan and
burr varieties are annual.

Some varieties, as alfalfa, crimson and sweet clover, are upright in
their habit of growth. Others, as the small white and the burr, are
recumbent. Others again, as the medium red, alsike and mammoth, are
spreading and upright. The alfalfa and medium red varieties grow most
persistently through the whole season. The sweet, small white and alsike
varieties can best endure cold, and the sweet, Japan and burr varieties
can best endure heat. The small white, Japan, burr and sweet clovers
stand highest in ability to maintain a hold upon the soil.

The minor points of difference are such as relate to the shape and color
of the leaves, the tints of shade that characterize the leaflets, the
shape and size of the heads and the distinguishing shades of color in
the blossoms.

The characteristics which they possess in common are the high protein
content found in them, the marked palatability of the pasture and hay,
unless in the sweet and burr varieties, the power which they have to
enrich and otherwise improve soils, and the honey which they furnish.

=Plan of Discussion.=--Chapter I., that is, the present chapter, as
already indicated, is introductory, and outlines the nature, scope and
plan of the work. Chapter II. deals with the general principles and
facts which relate to the growing of clovers. A close study of these
will, in the judgment of the author, prove helpful to those who engage
in growing any of the varieties of clover discussed in the book.
Chapters III. to XI. inclusive treat of individual varieties, a chapter
being devoted to each variety. It has been the aim of the author to
discuss them in the order of the relative importance which they bear to
the whole country and to devote space to them accordingly.

The following varieties are discussed and in the order named: Medium Red
clover, Alfalfa, Alsike, Mammoth, Crimson, Small White, Japan, Burr and
Sweet. All of these varieties will be found worthy of more or less
attention on the part of the husbandmen in the various parts of this
continent.

Chapter XII. is devoted to a brief discussion of miscellaneous varieties
which have as yet been but little grown in this country, or of varieties
of but local interest. The former are Sainfoin (_Onobrychis sativa_),
Egyptian clover (_Trifolium Alexandrianum_),