MUSCI. 



Subclass II. CELLULAIl ACKOGENS. 



Plants composed of cellular tissue only. Antheridia or archegoiiia, or both, formed 

 upon the stem or branches of the plant itself, which is develope.l from the germi- 

 nating spore usually with the intervention of a filiform or couferva-like prothallus. 



Ohdeh CXXVI. MUSCI. 



Low and mostly cespitose or tufted plants, caulescent and with distinct sessile 

 simple mostly 1-nerved leaves, alternate in several ranks or rarely distichous the 

 stems bearing spore-cases which contain only simple spores and open usually by a 

 <leci.luous hd. Inflorescence dioecious, montecious, or bisexual, involucrate and 

 mostly bud-hke, terminal or lateral, the reproductive organs accompanied by jointed 

 Idainents (paraph >/ses). Male flowers (involucre, when present, called the peri- 

 yomvm) of several (1 to 20) clavate i.ersistent antheridia, opening by an apical 

 sht and discharging a mucous fluid filled with oval colls, each containing an anther- 

 izoid. Female flowers (the involucre termed the perichaetium) of 1 to 20 flask-like 

 arclmjoaia (or pistillidia), each inclosing a nucleus and terminated by a funnel- 

 mouthed tube {.tyle), usually but one becoming f.-rtilized, when the enlarging nucleus 

 bursts the envelope and elongates, the lower part forming a slender pedicel°sheathed 

 by the base of the envelope {vagimde), the summit becoming a capsule bearing the 

 upper part of the archegonium as a calyptra. Cajisule rarely indehiscent or dehis- 

 cing by 4 valves, usually opening by a lid {operculum), whiJh leaves the mouth of 

 the capsule naked or surrounde.l by a ring {peristome) of usually 16 teeth, distinct 

 or coherent by pairs or more or less divided, with or without a variously divided 

 inner ring, the base of the peristome often encircled by an elastic ring of cells 

 {anmdus). The pedicel continues through the capsule as a columella, and is often 

 thirkoned under the base of the capsule, forming a collnm (or apophyus) or, if only 

 at one side, a struma. The calyptra either splits at one side (becoming cncullate, or 

 dimidiate if cleft to the apex), or remains entire and campanulate or mitre-shaped 

 {mitri/orm). The sporangium lin^s the cavity of the capsule and contains the spores, 

 which are formed by fours within mother-cells. Spores in germination producing a 

 confervoid branching prothallus, developing buds which become leafy stems. Propa- 

 gation also takes place by means of rjemmce, or by detached leaf-buds, or by the 

 formation of a new prothallus from the roots or from the root-like hairs {rhizoids) 

 which often abound upon the stems. 



An order of perhaps 150 genera and nearly 4,000 speries, .listributed over the entire globe, but 

 most abundantly in temperate an.l cooler regions. They love especially damp or shaded places 

 and are found upon rocks, trees, the ground, or in running streams, each genus or species having 

 ts pecu har preference They vary much in size, from srcms i of a line to 1 or 2 <\'et in len^f 

 bu in diameter only from ^ to A of a line. The stem is composed of more or less elongS 

 and narrow cells, the outermost layers usually much thickene.l and of a bright red or reddish 

 coloi-. It IS occasionally stoloniferous at base, more frcciuentiv brancliing nbovc and extendin<' bv 

 a series of vigorous lateral shoots or innovations. Tiie leaves are formed usuallv of a simi.le layer 

 ot cells with commonly a medial vein or casta, consisting of several layers. The tissue {nrrolation) 

 ot tlie blade IS homogeneous in each layer, though the cells may vary much in form and size in 

 tlie same leaf being usually larger and more elongated toward the base, as well ns thinner and 

 destitute of chlorophyll. Cells which are placed end to end are said to be proscnchimatomt • those 



