174 BRITISH FERNS. 
water easily carried off by means of a stop-cock, 
which could be turned when necessary. Other most 
important measures were to regulate light and tem- 
perature. The case was placed in a lobby, where ~ 
it received only a subdued light, with but partial rays 
of the sun through the medium of green glass, and 
where the temperature was generally even throughout 
the year, for the plants would not bear excess of heat 
and cold: thus moisture, an equable temperature, and 
& modulated light were the essentials for effective 
tee 
45. TUNBRIDGE FILMY FERN. Toxpnivcenss. 
‘Trichomanes tunbridgense, Linneus. B. F. 207, 
The radicles are black, wiry and very slender: the 
caudex is long, black, slender, wiry and creeping. 
‘The fronds are drooping and pinnate; they consist of 
“branched series of veins, each being clothed with a 
‘membranous or filmy wing, the Structure in this 
respect being exactly similar to that of the Bristle 
‘Fern: the branches or pinnw are alternate, and each 
‘is more or less subdivided; the divisions or pinnules 
‘are mostly in pairs, and the two sides of each pinna_ 
are alike; the margin of the wing is crenulate, The 
masses of seeds are nearly round, and each is seated 
almost at the extremity of @ short vein which, in each 
