FEENS. 



289 



with thrips, as a recent experiment showed that- 

 submersion for twenty-foui- hours apparently had no 

 effect ; the little creatures were particularly lively 

 and active after the trial to which they had been 

 subjected. 



Practically speaking, Hymenophyllums are not 

 raised fi'om spores. It is true that one very success- 

 ful grower has succeeded in raising plants of two or 

 thi'ee species from spores, but the method is an 

 exceedingly slow one. Vigorous growers are readily 



From Hymenophyllum it principally differs in the 

 involucre being urn-shaped and not split lengthwise 

 into two valves. In both the spore-cases are clus- 

 tered around hair-Uke receptacles, which are, in fact, 

 the ends of the veins of the fronds projecting into 

 the urns. In Trichomanes it is usual for these 

 slender columnar receptacles to protrude more or 

 less, so that the fronds become somewhat bristly 

 when very full of fructification, and hence has arisen 

 the common name of Bristle Fern. On the other 



Tkichomanes eemforme. 



propagated by means of the numerous thread-hke 

 rhizomes ; and some of the species, if the old fronds 

 are fastened down on a moist surface, become proli- 

 ferous, and develop plantlets which can be removed 

 when large enough, and grown on. As a rule, the 

 plants offered for sale by nui'serymen are imported 

 ones, and these require somewhat different treatment 

 from their arrival until they become established. 

 Much less light is desirable until the rhizomes begin 

 to push out new fronds, when the plants may be 

 gradually inured to the conditions which are found 

 suitable for their established congeners. 



The Trichomanes. — In common with HjTneno- 

 phyllum, Trichomanes holds a high position in the 

 estimation of fern-lovers. The beautifully- cut and 

 pellucid fronds are different in texture and general 

 appearance from those of almost all other genera. 

 43 



hand, these hairs are shorter than the involucre 

 in Hymenophyllum. There are many filmy ferns 

 which cannot be referred to either genera with any 

 degree of certainty without fructification. 



In the " SjTiopsis Filicum " above ninety species 

 of Trichomanes are described ; they are principally 

 natives of tropical and damp warm climates, the only 

 European representative being the Killamey Fern, 

 T. radicans. The species mentioned below are the 

 most distinct now in cultivation. 



STOVE SPECIES. 



A number of these, formerly supposed to be 

 exclusively stove kinds, have been found to do 

 better in a cooler temperature ; they will be men- 

 tioned among the cool - house sorts. Those kept 

 under the above heading have not hitherto, I be- 

 lieve, been successfully cultivated except in structures 



