THE NATURAL CONDITIONS OF PLANTS. 41 
for perfect drainage, I carefully sprinkle the sur- 
face of the fronds with water once or twice a 
week in summer, and less frequently in winter, 
and keep the door of the case (which is very 
close) always shut, the drainage-valve underneath 
always open. The case stands in a vestibule 
with nearly west aspect, quite sheltered from 
the south by the house, which is much higher 
than the vestibule. I strongly think that much 
of my success is due to the fact that the light 
is much subdued by shining through coloured 
glass windows (the colour is chiefly brown and 
orange). The general appearance of the plant is 
quite natural, the fronds bending down mostly. 
About three years ago, I placed, for experiment, 
a small portion of the rhizome with one open 
frond, on a block, and hung it up in the case. 
It has now nineteen expanded fronds, varying 
from nine to twelve inches in length, the rhizome 
having crept all round the block, and throwing 
down abundance of roots five or six inches long. 
I have not found any other fern to thrive, or 
even to live, in this case, except Asplenium 
marinum, which seems to like the situation toler- 
ably. I have even tried Hymenophyllum Tun- 
hrigense and Wilsoni, neither of which lived past 
one year. The plant has never shown the least 
approach towards producing seeds, although I 
