FIUCES. 1»57 



partially open, disclosing the spores inside. Eiicli little globe is, 

 in fact, it spore-case or sporangium, so that lieie we liave some- 

 thing quite different from what we have so far met with. Up to 

 this point we have found the sporangia collected into dots or 

 lines or clusters of some sort. In the Moonwort the sporangia 

 are separate and naked, and instead of bursting through the 

 action of an. elastic ring, they open by a horizontal slit and 

 discharge their spores. In other Eerns, as the Osmunda, the 

 sporangia are somewhat similar, but burst open by a vertical 

 instead of a horizontal slit. 



Observe that the frond of Botryohium is not circinate in the bud . 



We shall now proceed to describe the commonly occurring ' 

 representatives of the Fern Family. 



Ordek CXII. FILICES. (Fekn Family.) 

 Flowerless plants with distinct leaves known a.s frOTuls, these 

 circinate in the bud, except in oiie suborder, and bearing on 

 the under surface or margin the clustered or separate sporangia 

 or spore-cases. 



Synopsis oT (lie Oriirrn. 

 Suborder I. POLYPODIA' CE^ffi. (The True FeRns.) 



Sporangia collected into various kinds, of clusters called soi-i. 

 Each sporangium pedicelled and encircled by an elastic jointed 

 ring, by the breaking of which the sporangium is burst and the 

 spores discharged. Sori sometimes covered by an indusimm. 



1. Polypo'diiini, Fruit-dots on the hack of the fronds near the ends 



ofthe veins.. Noindusinm. Veins free. (See Fig. 231, Part I.) 



2. A<Ilan'tuiu. Fruit-dots marginal, the edge of the frond being re- 



flexed so as to form an indusium. Mid,rib of the piminles clnse to 

 the lower edge or altogether wanting. Stipe hlaclc and shining. 

 All the pinnules distinct and generally minutely stalked. Veins 

 free. 



3. Ptc'rls. Fruit-dots marginal. Indusium formed by the reflexed 



edge of the frond. Midrib of the pinnules in the centre and 

 prominent. Veins free. Stipe light-coloured. (See Fig. 262.) 



4. PcIIw'a. Fruit-dots marginal, covered by a broad indusium, formed 



by the reflexed margin ofthe frond. Small ferns with once- or 

 twlce-plnnate fronds, the fertile ones very much like the sterile, 

 but with narrower divisions. Stipe shining, purple or brown. 



