IX. MUSCI. 921 



The affinities of Characeee are very obscure. A. L. de Jussieu placed them among Monoeotyledonous 

 Phaenoganis, near Naiadece ; R. Brown near Hydrocharidea ; some botanists have placed them near 

 Myriophyllum and Ceratophyllum, from having the same habitat, and resembling them in habit. Several 

 modern authors Wallroth, Von Martins, Agardh, Endlicher have classed them after Afffes, where Adr. 

 de Jussieu retained them, whilst observing that, in spite of their purely cellular structure, they recall 

 axiferous plants. Brongniart having regard to the fact that the stems and leaves of submerged 

 Phsenogams often are simple in structure as compared with terrestrial plants of the same families, thinks 

 that the structure of the stem of Characece ought not to determine their affinity, and that it is rather the 

 nature of their reproductive organs which should be considered ; whence he places these plants amongst 

 the highest Cryptogams, near Ferns and Marsileacece, or between these and Mosses and Hepaticce. 

 Cliaracece all grow in fresh water, or sometimes in the brackish waters of sea-coasts, and appear to extend 

 nearly over the globe. 



This family is nearly useless to man ; .some species of Chara are covered with calcareous salts, and 

 are used for polishing plate, whence their common name of Iferbe a ecnrer and Lustre tfemi. 



IX. MUSCL Dillenius, Hedwig. 



Cellular terrestrial or aquatic annual or perennial Acotyledons. STEMS erect 

 or prostrate, leafy. LEAVES alternate, or rarely distichous, sessile, simple. REPRO- 

 DUCTIVE ORGANS formed of antlieridia and archegonia, in the axils of bracteoles, 

 or from the centre of a common involucre (perigonium, perigynium) . INFLORESCENCE 

 polygamous, monoecious, or dioecious. ANTHERIDIA formed of shortly pedicelled cellular 

 sacs, opening at the top, and emitting a semi-fluid parenchyma, composed of cells 

 each containing an antherozoid. ARCHEGONIA flask-shaped, containing an embryonic 

 nucleus suspended in mucus. NUCLEUS formed of a cellular sac, which is transversely 

 ruptured ; the upper part is then raised by the rapid elongation of the embryo, whilst the 

 lower part forms at the base of the embryo a membranous sheath (vaginula), and sur- 

 mounts the fruit with a sort of cap (calyptra). FRUIT capsular (urn or theca) borne 

 on a pedicel (seta) ; seta sheathed at the base by the vaginula, and sometimes terminated 

 \below the urn~\ by a swelling (apophysis). URN spherical, ovoid, cylindric or pris- 

 matic, sometimes indehiscent, mostly furnished with a cover (operculum), which detaches 

 circularly when ripe, and leaves an orifice (peristome) ; axis of the urn occupied by a 

 cellular column (columella) rising into the operculum. PERISTOME naked, or furnished 

 with a separable border (annulus), and usually crowned with 4, or a multiple of 4 teeth 

 or hairs. SPORANGIUM enclosed in the urn, and formed of a double sac lining the walls 

 of the urn, and columella. SPORES in fours in the mother-cells, contained between the 2 

 sacs of the sporangium. 



STEM elongating in one direction, i.e. from below upwards, sometimes scarcely 

 perceptible (Buxbaumia, Phascum, Discelium, &c.), sometimes several feet long 

 (NecJcera, &c.), simple or branched, of equal diameter throughout, cylindric or tri- 

 gonous, variable in consistency and colour ; sometimes soft, watery and nearly 

 transparent (Schistostega, &c.), or green or reddish (Bryum, Splachnum, Mnium, &c.) ; 

 sometimes nearly woody and black (Polytrichum, Hypnum, Neckera, &c.). Axis of 

 the stem solely composed of more or less elongated and narrow fibrous cells ; the 

 outer superficial cells, which take the place of the epidermis, are thicker and of a 

 more or less intense red j they are often prolonged into aerial rootlets or appendages 



