SPECIAL WAYS OF GROWING FERNS. 115 



The Hymenophyllacecz (ferns of the genera Tri- 

 chomanes and Hymenopkylhtm], and also the Todeas 

 (which belong to the Osmundacece), require greater 

 protection than is afforded by the ordinary green- 

 house. Therefore bell-glasses or cases must be 

 arranged for them in some very shady place. The 

 cases must be water-proof on the outside, since 

 they will unavoidably be frequently wet while 

 other plants are being watered, or the drip from 

 the roof may fall on them. The earth in the cen 

 tre of the case in which these ferns are grown 

 should be somewhat raised, and small stones 

 added to furnish a support for the little running 

 stems to fasten to. Some species of Trichomanes 

 and Hymenophyllum will grow well on the trunks 

 of tree-ferns in the tropical house. Todea su- 

 perba and T. hymenophylloides are plants beautiful 

 beyond description. Without enumerating the 

 species of these genera, it is safe to advise simi- 

 lar treatment for all, and to say that any species 

 are desirable. They all require special care as to 

 drainage, and all like a loose, fibrous soil, with 

 some sand. As their fronds are only one cell in 

 thickness, they are too filmy to expose to any cur- 

 rents of air. They prefer to live in a kind of 

 steam-bath all the time, unless the earth they are 

 in is not too wet. They often succeed well in a 

 fernery, if a case can be devoted exclusively to 

 them ; and, if you can obtain the plants to fill such 

 a case, it is a piece of great good fortune. 



