206 
SUCCULENT PLANTS. 
those kept in it ; and that the lights can be removed or replaced without any 
trouble. The attendant disadvantages are exceedingly slight. One of the princi- 
pal is that the plants cannot be viewed comfortably in bad weather, and this is 
partly nullified by the walk before mentioned in the interior of the house ; while 
the injury that would accrue to the plants from having the shelves of the stage so 
nearly above each other, thus subjecting the specimens on one shelf to the droppings 
of the rejected fluids from those on the next higher shelf, can be obviated by per- 
forating the stage at certain intervals, and placing the hole of every pot just over 
the cavity in the shelf. With this simple modification, the house here described 
appears to us to combine, in an eminent degree, all the features which we had 
supposed worthy of consideration. 
Following out the proposed division of succulents into two classes, or such as will 
require a high temperature, and those which will succeed with a much lower one, 
the former of these groups may be made to include all the Cactacese, of which we 
shall at present restrict our attention to the dwarfer and more compact forms, 
leaving the Epiphyllous sorts for subsequent dissertation. It may suffice to say 
that the species of Mammillaria, Echinocactus, and Melocactus, constitute the types 
of what we now wish to remark upon, and that all which assimilate to them in 
shape, will fall beneath the following observations. 
We have long held it as a principle in floriculture, that as near a conformity to 
the dictates of Nature as can be attained, and as comports with the altered circum- 
stances in which plants are placed, considering our knowledge of the effect of those 
conditions, should ever be sought. This position may be opposed by practical 
persons, who contend that we cannot produce a climate in all respects like that 
enjoyed by many tropical plants, and that therefore we should not strive to 
imitate too closely any single characteristic : but when any very prominent pecu- 
liarities are discernible, and we find ourselves capable of creating similar ones 
w^ithout either personal difficulty or danger to our charge ; if we then neglect to do 
so, we abandon the most proper and rational mode of culture, and may anticipate 
a partial or decided failure. 
Applying this assumption to the plants whose treatment is now under discussion, 
it is pretty generally known that they abound in climates where, for two or three 
months of the year, a constant rain falls, and both the earth and the atmosphere 
are filled with moisture, while the temperature is maintained at a high rate. 
Such is their actual growing season ; during which they enlarge themselves with 
unusual speed, and at its termination relapse into that torpidity which is essential 
to support them in the arid period which intervenes between that just alluded to, 
and a parallel one in the ensuing year. In our collections, instead of furnishing 
them with vigorous excitement for a short time, in accordance with the natural 
procedure, we keep the atmosphere of the house but very little more moist in the 
summer than in the winter ; the heat of the sun evaporating the fluids administered 
in the first stage, and the temperature being insufficient in the second to dispel the 
