CULTIVATION. 
389 
moisture to the absorbent, undisturbed air above it, 
which becomes more or less saturated, as dependent 
upon changes of temperature, and thus becomes 
proper for the growth of plants. 
The case may be constructed of any shape or size, 
according to taste or means ; it can be square or 
round, an octagon or hexagon; the roof may be a dome, 
span, or sloping, but by all means avoid a flat one ; 
and be the shape whatever it may, the design should 
in every point be neat, and not of such an ornamental 
description as to be more attractive than the plants. 
A very good, interesting collection may be grown 
in one 3 ft. long by II ft. in width, and 2 1 feet high; 
it will have the best appearance if the sides are con- 
structed with single squares of glass ; but if divided, 
it must not be into more than three, as many 
divisions spoil the effect ; the ends should be made 
to open, to enable any dressing or removing of old 
fronds to be done conveniently, and a small piece of 
perforated zinc should be inserted in the apex of the 
roof at each end, which will assist in preventing the 
almost universal complaint, that the plants cannot be 
seen for condensed water on the inside of the glass ; 
this is caused by the variation of temperature. If 
the case stands in the sun or becomes warm inside 
during the day, and retains the heat, whilst the 
temperature of the room may fall considerably during 
the night, the cold air, acting upon the glass, con- 
denses the warmer vapour inside and obscures the 
plants. By the introduction of the above-named 
remedy the temperature is more equally balanced, 
and the plants are always to be clearly seen. Should 
the air outside become very hot and dry, it will be 
