384 
FERNS : BEITISH AND FOREIGN. 
summer, but taking care to prevent currents of dry air. 
I have now stated tbe chief points to be observed 
in forming and arranging an indoor natural Fernery, 
tbe principles of which are capable of application to 
houses of the ordinary construction and usual average 
size, or to any extent that means will allow ; even to 
realize the grand idea of the celebrated Loudon, who, 
more than thirty years ago, speaking in favour of span- 
roofs, said, “ There would be no difficulty in covering 
fen acres of Kew Gardens with glass by a series of 
span-roofs/’ Although since then much has been 
done at Kew, by the erection of lofty plant-houses, 
still the area covered falls far short of ten acres ; but 
as natural cultivation is now patronized, and with 
the improving age and desire for novelty, let us hope 
that the time is not far distant when Kew may have 
at least one acre converted into a straight or winding 
Fern-valley covered with glass, the highest part not 
to exceed thirty or thirty-five feet above the centre of 
the valley, that being sufficient height for such Tree 
Ferns as may perchance withstand the vicissitudes of 
thirtv years careful treatment. 
In a house of this kind, furnished with means of 
maintaining a temperature of 60 in the coldest weather, 
situations in it would be found suitable to the good 
growth of not only Ferns and Aroideoe, but also 
Bromeliacece, Orchids , and other kinds of plants of an 
epiphytal nature. 
For an open-air Fernery a sheltered situation should 
be chosen, and if possible within the influence of 
shelter and shade, but not under trees ; a sloping bank, 
a natural or artificial hollow, such as an old gravel-pit 
or sunk fence, may be turned to good account. The 
