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 1^ ft. in width, and 2\ 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 ba 



