remembered that all this happened in the dry atmosphere of a museum, it
will be apparent how exceptional Cactuses are in their manner of growth,
and in the wonderful tenacity of life they exhibit under conditions
which would destroy the majority of plants in a very short time. We
sometimes find, when examining the bases of Cactus stems, that decay has
commenced; this is carefully cut out with a sharp knife, and the wound
exposed to the action of the air till it is perfectly dry, or, as we
term it, "callused."

Watering.--It will have peen gathered from what has been previously
said in relation to the conditions under which the majority of the
plants of the Cactus family grow when wild, that during their season of
growth they require a good supply of moisture, both at the root and
overhead; and afterwards a somewhat lengthened period of rest, that is,
almost total dryness, accompanied by all the sunlight possible, and
generally a somewhat high temperature. The growing season for all those
kinds which require to be kept dry when at rest is from the end of April
to the middle of August, and during this time they should be kept
moderately moist, but not constantly saturated, which, however, is not
likely to occur if the water is not carelessly supplied, and the
drainage and soil are perfect. This treatment corresponds with what
happens to Cactuses in a wild state, the frequent and heavy rains which
occur in the earlier part of the summer in the American plains supplying
the amount of moisture necessary to enable these plants to make fresh
growth, and produce their beautiful flowers and spine-clothed fruits.
After August, little or no rain falls, and the Cactuses assume a rather
shrivelled appearance, which gives them an unhealthy look, but which is
really a sign of ripeness, promising a plentiful crop of flowers when
the rainy season again returns.