45 
direct exposure to the sun. 
vated with the aid of some shade tree. Filmy ferns at Kew are at 
once killed by direct sunlight. But shading and altering the composi- 
tion of the light are by no means the same thing. 
The use of green glass at Kew involved a curious practical difficulty. 
It is almost impossible to obtain glass which is absolutely free from 
manganese. But the green glass which of late years at any rate has been 
employed at Kew, is almost certainly coloured with iron protoxide. 
Manganese is used in the manufacture, in the form of manganese dioxide. 
There are no doubt plants which require shade and will not tolerate 
n the tropies > culti 
finds that a specimen examined by him “cuts off, very slightly, at red 
end, and generally throughout the spectrum.” Ina specimen in which the 
decolourisation had been completely effected, he found “ no appreciable 
effect on any portion of spectrum to. the eye.” It had, in fact, become 
practically identical with ordinary white glass. 
Yunnan Plants.—An old Chinese correspondent of Kew, Mr. W. Han- 
cock, F.L.S , to whom it is indebted fer several small collections of dried 
Chinese plants, has sent a further collection, comprising about 150 
species of flowering plants and 120 ferns. The specimens are admirable, 
and often copious. ‘These plants were collected in the neighbourhood of 
Mongtze, or * Mengtsz," as Mr. Hancock writes it. "This place is 
m @ cursor 
the collection that it contains a considerable sprinkling of undescribed 
ones. There are probably at least 10 new terns, a large number con- 
_ sidering the wide range of ferns generally. Among flowering plants a 
spicuous. It has primrose-yellow flowers with broad overlapping petals 
of great substance, and they are from " inch to 12 inch in diameter 
o 
racemes of “rich red” flowers. A Rhododendron having very 
The very large and distinct Rosa gigantea, Collett, is also 
pos , 
among the plants collected. Some ot t 
be Mid in an early part of Hooker's Icones Plantarum. 
Perim Plants—Mr. J. B. Farmer, F.L.S., Assistant Professor of 
Botany, Royal College of Science, South Kensington, had an opportunity 
of landing on this island on his return from Ceylon a few years ago, and 
u 85826. c 
