228 
SUCCULENT PLANTS. 
Immediately after the diminution of the supply of heat and water to the ratio 
of that of the external air, all the subjects of this dissertation are to be removed 
thereto, with the view, already indicated, of checking the further elongation of 
their stems, abstracting a portion of their fluids, and causing the rest to resolve 
themselves into the peculiar nature of the plant, and form the rudiments of future 
flowers. It may very truly be said that warmth and moisture are much needed 
by Cactacese in summer to promote their enlargements ; but w^hen speaking of 
autumnal exposure for the purpose of rendering them floriferous, we must adopt 
stronger expressions, and consider it as a sine qua non. 
An excellent proof of the preceding statement occurred beneath our cognizance 
a short time since. An old specimen of Epiphyllum speciosum was turned into the 
open air in the month of August, and there abandoned to its fate. On the approach 
of frosts, however, it was carelessly thrown into a dry shed, and again cast out 
from thence in the ensuing spring. The plant then exhibited a most miserable 
appearance ; the leaves being browned and shrivelled, and death being obviously 
inevitable. In a few weeks, notwithstanding our anticipations, the showers of 
rain and the mildness of the atmosphere restored it, and it blossomed in the summer 
more profusely than any specimen which had been carefully nursed. 
In bringing forward the case jnst cited, our main design is to show that prudent 
exposure is of the greatest benefit to Epiphylla. Had the autumn of the season 
mentioned not been a very dry one, detriment rather than advantage would have 
resulted to the plant. Hence, though we advocate the transference of these objects 
to the open air, we must be understood to qualify this by assuming that they have 
something over or near them by which they can be protected in wet weather ; for 
the good effects of the sun's action upon them would be immensely overbalanced, 
if they were at the same time unsheltered from heavy rains. Indeed, direct 
solar light will be of less service to them than aridity ; but, in conjunction 
therewith, it is an important assistant to prolificness, and should by all means be 
obtained. 
Considering the circumstances herein displayed, rather than turn Epiphylla 
entirely out of the houses or frames in which they may be growing, we would take 
the lights from these about the month of August, and leave them exposed, except 
when the weather is showery, till frosts become frequent. We give preference to 
this plan because, by placing Cacti completely in the open air, they cannot be 
easily screened from rain ; and the subjection to wet of any kind is to be looked 
upon as the most serious evil which could befal them. Besides, by standing 
uncovered during the night, they suffer all the injury which can accrue from a cold 
damp air. We are aware, that in the last declaration we place our opinion in 
opposition to the popular one, which supposes that the influence of cold assists 
much in imparting a character of utility to exposure in autumn, by checking the 
disposition of the plants to make further progress : but we steadily maintain that 
light, heat, and dryness, are the sole agents in ripening the immature growth, and 
