62 BOTANY. 



imbedded in the frond, or situated on rounded, sessile, and stalked receptacles. 

 2. Pistillidia, either inclosed in involucres and solitary, or occurring at the 

 edge of the frond, or on the lower side of stalked peltate expansions. Thecoe 

 or developed pistillidia, having no operculum, opening irregularly, or by 

 four valves. Spores often mixed with spiral filaments called elaters. He- 

 terorhizal in germination. Terrestrial plants found in damp places, or 

 inhabiting water ; some having a moss-like ajipea ranee. They are natives 

 both of cold and warm climates, and arc generally distributed over the 

 globe. 



Sub-order 1. Jun^ermanniece, or scale mosses. Frondose or foliaceous 

 plants, terrestrial or on trees. Capsule dehiscent lengthwise into four valves. 

 Jungermannia, the principal genus, is represented by many species : Gym- 

 noscyphus, one of the true Jungermannieae, is represented in jtl- 54, fig. 43, 

 by G. repens. 



Sub-order 2. MarchantiecB. Frondose and terrestrial ; perennial, growing 

 in wet places, with the fertile receptacle raised on a peduncle, capitate or 

 radiate, bearing pendent calyptrate capsules from the under side, which 

 open variously, not four-valved. Elaters with two spiral fibres. Ex. 

 Marchantia polymorpha {pi. 54, fig. 44), very common in shaded, moist 

 places. 



Sub-order 3. Anihocerotem. Terrestrial frondose annuals with the fruit 

 protruded from the upper side of the frond ; perianth none. Capsule pod- 

 like, single or double-valved, with a free central columella. Elaters none or 

 ^imperfect. Ex. Anthoceros punctatus {pi. 54, fig. 42), found on wet slopes 

 and the sides of ditches throughout the United States. 



Sab-order 4. Ricciea'. INIostly frondose floating little annuals, with both 

 kinds of flowers, and the fruit immersed in the frond. No involucre, perianth, 

 nor elaters. Capsule bursting irregularly. Ex. Riccia. 



Sub-order 5. Monoclea. Fruit, solitary capsular, opening laterally by a 

 longitudinal slit. Elaters, mixed Avith spores. Vegetation, foliaceous or 

 frondiform. Ex. Monoclea. 



Order 5. Musci, 3Iosses. Plants having a distinct axis of groAvth, often 

 giving off branches or innovations ; no vascular system. Leaves minute and 

 imbricated, entire or serrated, sometimes with condensed cells, in the form 

 of ribs or nerves. Reproductive organs of two kinds : 1. Antheridia, 

 cylindrical or fusiform stalked bags, containing powdery matter and phy- 

 tozoa, and mixed with empty jointed filaments or paraphyses. 2. Urn- 

 shaped pistillidia, inclosed at first within a calyptra. which is ultimately 

 carried up with them, leaving often a sheath round the bottom of the fruit 

 stalk. These pistillidia finally become the theca}, or spore-cases, supported 

 on a stalk or seta, which has leaves at its base, called perichgetial leaves ; 

 on removal of the calyptra the theca is found to consist of a case with an 

 operculum or lid, which, when it falls off, shows the mouth of the urn, either 

 naked or crowned with a peristome, consisting of one or more rows of teeth 

 (in number four, or a multiple of four), distinct or united in various ways. 

 In the centre of the theca is a columella, and the bag formed between it and 

 the parietes of the theca contains spherical cells, called spores, each of 

 62 



