344 FERNS : BRITISH AND FOREIGN. 



examples of the superiority of this mode of growing 

 plants over that of pot culture; by proper arrange- 

 ment from ordinary level positions, their delicate hue 

 and elegant form of outline may be seen to much 

 greater advantage, as the upper surfaces of their 

 fronds are generally presented to the eye more fully. 

 And where this system is largely carried out, if a 

 raised platform or footway be erected considerably 

 above them, the advantage is still greater. The great 

 beneficial influence this system has on the plant is 

 mainly consequent on the more uniformly moist at- 

 mosphere, so congenial to all Ferns, which can be 

 successfully maintained from the great extent of the 

 more natural evaporating surface of the soil, and ma- 

 terial, with which the rockery is composed ; and as they- 

 are allowed to establish themselves at freedom in it, 

 there is a similar uniformity of temperature at the 

 root, as well as of moisture. As is well known, in 

 large masses of earthy and other solid material, its 

 temperature does not fluctuate with that of the house, 

 at least, as in the case with ordinary-sized pots of soil, 

 where the absorption and radiation of the heat takes 

 place so much more rapidly. It may further be men- 

 tioned, that, in a house entirely devoted to the cul- 

 tivation of Ferns under this system, its evaporating 

 surface does not wholly consist of the principal mass of 

 material composing the rock work ; there is the large 

 extent of wall- surface, which, if properly constructed 

 with rough and absorbent material, is continually 

 giving off its moisture, besides, from that reason, 

 affording an excellent opportunity for Ferns of more 

 or less scandent habit to assume their native character 

 in luxuriant profusion, by growing on it as on natural 



