Xll 
INTRODUCTION. 
— that of an atmosphere tolerably free from smoke ; on 
three sides, — east, south, and west, — there is a straight 
brick wall ; on the north there is an artificial mound, tole- 
rably covered with shrubs ; to the east, beyond the wall, 
are some large lime-trees, which completely shut out a 
summer morning’s sun ; at noon, the south wall casts its 
shadow on those Ferns which are planted purposely within 
its reach, and these can only be illuminated for a single 
half hour, when a summer sun is sinking unclouded in the 
north-west. Within the space enclosed by the walls are 
sundry buildings, by courtesy denominated rock-works, 
but which are in fact close imitations of the most unpictu- 
resque stone walls that ever deformed the face of a hedge- 
less country. In Scotland I have seen such walls, when 
built against a bank to prevent its crumbling into a newly 
cut road, covered with a continuous garden of our most 
beautiful Ferns ; Athyrium Filix-femina, Polypodium 
Phegopteris and P. Dryopteris, Lastrma Oreopteris and 
L. muUiJlora, Cystopteris fragilis, and Allosorus crispus, 
I have seen crowded together for hundreds of yards : the 
water from the land above is continually filtering through 
the walls, and thus the roots are supplied with a perpetual 
moisture. Witli a view of imitating this on a small scale, 
my formal walls have been built ; each is slanting at a 
slight angle from the perpendicular, and they face different 
points of the compass. One, situate under a thick Portu- 
gal laurel, has never yet been visited by a ray of sunshine — 
“ The beams of the warm sun j)lay round it in vain ; ” 
