t point in favour of the plants of the Cactus family for gardens
of small size, and even for window gardening--a modest phase of plant
culture which has made much progress in recent years--is the simpleness
of their requirements under cultivation. No plants give so much pleasure
in return for so small an amount of attention as do these. Their
peculiarly tough-skinned succulent stems enable them to go for an
extraordinary length of time without water; indeed, it may be said that
the treatment most suitable for many of them during the greater portion
of the year is such as would be fatal to most other plants. Cactuses are
children of the dry barren plains and mountain sides, living where
scarcely any other form of vegetation could find nourishment, and
thriving with the scorching heat of the sun over their heads, and their
roots buried in the dry, hungry soil, or rocks which afford them
anchorage and food.

In beauty and variety of flowers, in the remarkable forms of their
stems, in the simple nature of their requirements, and in the other
points of special interest which characterise this family, and which
supply the cultivator and student with an unfailing source of pleasure
and instruction, the Cactus family is peculiarly rich.

CHAPTER II.

BOTANICAL CHARACTERS.

Although strictly botanical information may be considered as falling
outside the limits of a treatise intended only for the cultivator, yet a
short account of the principal characters by which Cactuses are grouped
and classified may not be without interest.

From the singular form and succulent nature of the whole of the Cactus
family, it might be inferred that, in these characters alone, we have
reliable marks of relationship, and that it would be safe to call all
those plants Cactuses in which such characters are manifest. A glance at
some members of other families will, however, soon show how easily one
might thus be mistaken. In the Euphorbias we find a number of kinds,
especially amongst those which inhabit the dry, sandy plains of South
Africa, which bear a striking resemblance to many of the Cactuses,
particularly the columnar ones and the Rhipsalis. (The Euphorbias all
have milk-like sap, which, on pricking their stems or leaves, at once
exudes and thus reveals their true character. The sap of the Cactuses is
watery). Amongst Stapelias, too, we meet with plants which mimic the
stem characters of some of the smaller kinds of Cactus. Agai