HISTOEY OP INTRODUCTION OF EXOTIC FERNS. 27 



?, including P. contignum and P. Emc-rsoni, 

 which, oil account of their sporangia being seated in 

 a deep cyst, and protruding outwards, are referred by 

 some authors to Davallia. Two fine Tree-ferns are 

 also worthy of notice, Alsophila crinita and Cyathea 

 Wallteri. Many of the islands of the Eastern Archi- 

 pelago likewise offer a fertile field for the fern 

 collector, being rich in species of Hymenophyllum, and 

 Trichomanes, Asplenium, Lomaria, as well as in Tree- 

 ferns of the genera Oyathea and Alsophila. The one 

 or more Surnatran Ferns yielding the singular styptic 

 drugs brought to this country of late years under the un- 

 couth names of Penghawa, Djambi, and Pakoe Kidang, 

 would be of interest to cultivators from their beauty, 

 and to pharmaceutists from their properties. Cibotium 

 djambianum, Dicl'sonia chrysotricha, and two other 

 species of Alsophila (A. lurida and tomentosa) have 

 been mentioned as the sources of these drugs ; but 

 very little is known respecting any of them, and 

 more information is desired. Two singular and 

 peculiar Ferns widely spread throughout this region 

 are Tcenitis blechnoides and Osmunda Javanica, which, 

 .although long known in herbaria, have not yet 

 found a place in our living collections. The Moluc- 

 cas and Celebes, especially, possess large numbers ; 

 and among those in the former is the rare Cystodium 

 sorbifolium, known only from a few imperfect spe- 

 cimens from these islands, and from the island of 

 Honimoe. Mauritius contains several which would be 

 acceptable in our gardens ; but, with such an enthu- 

 siastic explorer as Mr. Duncan in that island, it is 

 to be hoped that they will not long be classed 

 ;among our desiderata. I would particularly call atten- 



