proportion of the 200 kinds known are not
cultivated in European gardens, and perhaps for many of them it is not
possible for us to provide in our houses the peculiar conditions they
require for their healthy existence. But there are a good many species
of Cereus represented in gardens, even in this country, and among them
we shall have no difficulty in finding many useful and beautiful kinds,
such as may be cultivated with success in an ordinary greenhouse or
stove. Lemaire, a French writer on Cactuses, groups a number of species
under the generic name of Echinocereus; but as this name is not adopted
in England, it is omitted here, all the kinds being included under
Cereus.

THE NIGHT-FLOWERING SPECIES.

The most interesting group is that of the climbing night-flowering
kinds, on account of their singular habit of expanding their flowers in
the dark and of the very large size and brilliant colours of their
flowers. In habit the plants of this set are trailers or climbers, their
stems are either round or angled, and grow to a length of many feet,
branching freely as they extend. By means of their roots, which are
freely formed upon the stems, and which have the power of attaching
themselves to stones or wood in the same way as ivy does, these kinds
soon spread over and cover a large space; they are, therefore, useful
for training over the back walls in lean-to houses, or for growing
against rafters or pillars--in fact, in any position exposed to bright
sunlight and where there is a good circulation of air. Soil does not
appear to play an important part with these plants, as they will grow
anywhere where there is a little brick rubble, gravel, or cinders for
their basal roots to nestle in. They have been grown in the greatest
luxuriance and have produced flowers in abundance with nothing more than
their roots buried in the crumbling foundations of an old wall, upon
which the stems were clinging. The chief consideration is drainage, as,
unless the roots are kept clear of anything like stagnation, they soon
perish through rot. During the summer, the stems should be syringed
morning and evening on all bright days, whilst in winter little or no
water will be required.

Like all other Cactuses, these plants may be propagated by means of
large branches, which, if placed in a porous soil, will strike root in a
few weeks. We saw a very large specimen of C. triangularis, which last
autumn suddenly rotted at the base, from some