i^ILMY FERNS. 



103 



We have been assured that such is not the case, and that 

 they will succeed in pots in a greenhouse, if not exposed 

 to sunshine, if well drained, by filling one-third of the pot 

 with drainage material, and if the soil is never allowed to 

 become quite dry. 



THE FILMY FEBNS. 



Spore-cases encbsed in a two-valved receptacle, which is borne on the 

 edge of the fronds. 



There is always an interest associated with the little 

 rilmy Ferns. Their delicate texture, local distribution 

 almost equal to rarity, diminutive size, singular mode of 

 fruiting, retiring disposition, and, until recently, unsuc- 

 cessful cultivation, have all helped them to notoriety. 

 Botanists have constituted for these ferns and their allies 

 a special sub-order, and with them also they are plants of 

 interest. The generic name of Hymenopliyllum is of 

 Greek origin, and means literally " membrane-leaved." 

 One point of structure in which these ferns difter from 

 all the species enumerated, possessed with a ring to the 

 spore-cases, is, that the ring in both the Filmy Ferns and 

 the Killarney Fern passes round the spore-case in an 

 oblique manner instead of being vertical. It is on this 

 account that a special sub -order has been set apart for 

 their reception. The principal points of difference be- 

 tween the Filny Ferns and the Killarney Fern are found 

 in the form of the kind of receptacle which contains the 

 spore-cases. In both instances the spore-cases are pro- 

 duced at the edge of the frond, and in both the spore-cases 

 are enclosed in a kind of capsule or receptacle. In the 

 Filmy Ferns this receptacle is two-valved, and in the 

 Killarney Fern it is cup-shaped and entire. The singular 

 appearance of this kind of fructification is calculated to 

 puzzle the b3ginner, and cause him to wonder whether 

 such can really be ferns. 



These little plants are so diminutive that they are almost 

 as much likd mosses as ferns to the uninitiated, and the 

 delicate texture of the leaves serves to strengthen such 



