FERNS 
145 
flat rafts made of open woodwork. On these the soil can be packed 
round the roots into a sort of mound, which not only gives the rhizomes 
abundant space to spread, but enables ample supplies of water to 
be furnished without any danger of producing a sour, stagnant state 
in the soil, which is apt to occur when ordinary pots are used. This 
plan, in short, combines many of the advantages of planting out, 
with the convenience of pot-culture. In a wild state ferns are often 
found in shady places, but in most cases the reason of this is that 
they are seeking for shelter and moisture rather than shrinking from 
sunlight. Under cultivation in Great Britain it is found that they 
should be treated in regard to light and shade pretty much as other 
greenhouse plants are treated. A time when careful shading is very 
necessary is when the tender, delicate young fronds are unfolding. 
But it has been abundantly proved that the permanent exclusion of 
pure sunlight by the use of green glass was an unfortunate error. 
The group of ferns known as “ filmy,” from the wonderful delicacy 
of their almost transparent fronds, are real shade-lovers. So sensitive 
Film Ferns ^ r T ness are they that they require to be grown 
y ' in glass cases, where the atmosphere can be kept as 
near saturation point as possible. Nor should the direct rays of the 
sun ever reach them. At Kew most of them are cultivated in a small 
house built against the north side of the tropical-fern house in 1892. 
It is 50 feet long and 14 feet wide, and each side of the central path 
is occupied by a glass case in which the ferns are cultivated. 
u 
