bone, which, when the necessary resting period comes round, either rots
or gradually dries up. In preparing soil, therefore, for all Cactuses
(except Epiphyllum and Rhipsalis, which will be treated separately) a
good, rather stiff loam, with plenty of grass fibre in it, should form
the principal ingredient, sand and, if obtainable, small brick rubble
being added--one part of each of the latter to six parts of the former.
The brick rubble should be pounded up so that the largest pieces are
about the size of hazel nuts. Lime rubbish, i.e., old plaster from
buildings, &c., is sometimes recommended for Cactuses, but it does not
appear to be of any use except as drainage. At Kew its use has been
discontinued, and it is now generally condemned by all good cultivators.
Of course, the idea that lime was beneficial to Cactuses sprang from the
knowledge that it existed in large quantities in the soil in which the
plants grew naturally, and it is often found in abundance, in the form
of oxalate of lime, in the old stems of the plants. But in good loam,
lime, in the state of chalk, is always present, and this, together with
the lime contained in the brick rubble, is sufficient to supply the
plants with as much as they require.

For Epiphyllums and Rhipsalis, both of which are epiphytal naturally,
but which are found to thrive best in pots in our houses, a mixture of
equal parts of peat and loam with sand and brick rubble in the same
proportion as before recommended, will be found most suitable. Leaf
mould is sometimes used for these plants; but unless really good it is
best left out of the soil. The finest Epiphyllums have been grown in a
soil which consists almost wholly of a light fibry loam, with the
addition of a little crushed bones.

Potting.--Cactuses, when healthy, are injuriously affected by frequent
disturbance at the roots. On the arrival of the potting season, which