162 
IMPROVEMENTS IN GRAFTING CACTI. 
It must likewise be a point in the cultivator's attention, that plants plunged in 
a heating material be not kept in pots of too small a description, or too long in the 
same place without examination ; because, in consequence of the stimulus bottom- 
heat gives to the roots, these, if not duly furnished with room to extend themselves 
in the pots, will often grow through the aperture at the bottom, and extend them- 
selves far into the bed. When they come to be removed from thence, the best 
supporters of the plant will, in such case, have to be entirely taken away ; and, 
where the species is at all delicate, the specimen will be seriously thrown back. 
Perhaps the simplest, easiest, and least questionable mode of giving bottom- 
heat to stove-plants in the summer, is by keeping them in pits or frames at that 
time, and filling up the houses with annuals and those other species which happen 
to be then in flower. It is at least certain that the trouble and expense of such a 
plan would be less, that the plants would be greatly advantaged by it, and that 
all houses seem most appropriately furnished during summer, when they are filled 
only with flowering objects. 
If frames were selected for the purpose, the heat might best be derived from a 
dung-bed, made up like those for melons and cucumbers, and kept up to the 
required temperature by what are termed linings, after the heat of the bed itself 
had lessened. It is notorious how beautiful Gardenias and other plants flourish in 
a dung-heat ; and there can be no doubt that most stove species would gain a 
verdure and healthiness in such circumstances, which are not to be obtained but 
by measures of this character. 
IMPROVEMENTS IN GRAFTING CACTI 
So extensively has the practice of grafting Cacti been adopted of late years, that 
it has ceased to be a matter of wonder, and no one would now be surprised to 
see any strange combination of the species of this tribe. As the experience of 
cultivators deepens, however, considerable modifications of existing systems are 
efiected ; and many of the older methods of procedure are laid aside, to make way 
for more approved plans. 
Formerly, the Pereskia aculeata, from its decidedly woody and shrubby nature, 
and from its producing a goodly number of vigorous roots, was almost the only 
stock on which Cacti were grafted ; the object of the process being to obtain a 
curiosity, or, in the case of some kinds, as Epiphyllum truncatum^ to secure a more 
healthy condition for the plant by putting it on a less delicate stock, and one whose 
roots were less susceptible of injury. More recently, it has been ascertained that 
some of the stronger-growing kinds have the healthiest possible roots if potted in 
a richer and more suitable compost than the miserable soil which was once given 
them ; and that, by using them as stocks, an important improvement in culture may 
be efl'ected, concurrently with the attainment of additional safety to peculiar species. 
