8 
became necessary to renew the east wing of No. II. 
house. In order to secure greater durability it was 
decided to use iron for the principal framework, and 
wood only for the lights. The top-ventilation was pro- 
vided for by means of a lantern instead of by the older 
and more clumsy method of sliding sashes. At the same 
time the use of green glass in the re- constructed wing 
was abandoned. This was introduced at Kew in 1846 
on the recommendation of the late Mr Eobert Hunt, 
F.RS., who advocated its use on theoretical grounds which 
are new known to be mistaken. The resulting improve- 
iiient in the growth of the plants, especially the species 
of J.dm'T^ifum was very marked, and in 18.92 a portion 
of the west wing was re-glazed with equally satisfactory 
results. 
The Temperate Ferns are now collected in a house 
(No. III.); which was also built on the system of mixed 
iron and wood construction. It was erected in 1892 to 
take the place of a decayed and obsolete structure com- 
posed of two small greenhouses united together, Nos. 4 
and 5 of Dr. Lindley's Report. The former (the northern 
wing) was erected in 1803, and in 1840 contained JS'ew 
Holland and Cape plants ; the latter, which was 
remodelled " in 1825, was filled with succulents. 
The reconstructed No. III. is a span-roofed house 
60 feet long, 23 feet wide, and 13 feet high. It contains 
a broad central and two side stages, with paths on both 
sides. 
The north wing of the former No. III. had been lattei ly 
devoted almost exclusively to Filmy Ferns after the Kew 
collection had been enriched by the gift of that formed 
