ON FERNS. 535 



unwise to weaken the substance of the fronds by subjecting the 

 plants to the influence of permanent artificial shading. 



Sometimes, however, the ferneries are so built or so dis- 

 posed that it is very difficult to shade them by means of blinds ; 

 in such cases permanent shading, with all its drawbacks, must 

 be resorted to, as scorching or bleaching must be avoided by 

 any possible contrivance. Although most Ferns are naturally 

 adverse to strong light, it is now acknowledged . that in the 

 construction of a fernery the use of ground or rolled glass 

 should be avoided. Numerous experiments have been tried with 

 the object of dispensing with shading, when ground-glass had 

 been selected as the best means of producing an even and 

 diffuse light, but its use in most cases, if not in all, has had to 

 be discontinued. When permanent shading must be used, white 

 should be selected ; green may produce a heavier shade, but 

 this is beneficial only for a small portion of the time the sun is 

 on the glass, as at other times it keeps out too much light, even 

 when a thin coating only is put on. Cream colour is better 

 than green ; but the best is white, for it allows more light to 

 penetrate on a wet or dull day, and this is a matter of great 

 importance to the health of the plants. Whenever possible, 

 the exotic fernery should be below the level of the ground. The 

 beauty of the Ferns is seen to best advantage when looked 

 down upon ; this disposition also ensures uniformity of tempera- 

 ture and permanency of moisture, both conditions most beneficial, 

 but very difficult to obtain or to maintain in houses built above 

 ground, especially when, as is generally the case, these structures 

 are supplied with shelves and open stages. The exotic fernery 

 may be intended for growing Ferns either in pots or when planted 

 in the natural way. Preference should be given to the latter mode 

 of culture, as a decided advantage in connection with the natural 

 fernery is that, when planted in rockwork, Ferns require a great 

 deal less attention than when grown in pots, and if provided 

 with suitable soil at the outset they will, with the help of an 

 occasional surfacing, flourish for years, and attain a size consider- 

 ably larger than when grown in pots. Sandstone, tufa, or even 

 limestone, may be used for building the rockery, while either 

 clinkers or pieces of coke dipped in thin cement are sometimes 

 used for that purpose, but they are only poor substitutes for 

 stone, as they lack the porosity so beneficial to the well-being of 

 the plants. Whenever the fernery is of sufficiently large 

 dimensions, the walks should undulate and wind to and fro ; 

 they should be made of stone, with rugged steps here and there, 

 the stone rising on each side to give the whole a more natural 

 appearance. 



Light — Of whatever dimensions the exotic fernery may be, 

 and whatever may be the style adopted for the building of the 

 rockery in it, it should be borne in mind that the principal 



