SPHAGNACE^. 



[ 708 ] 



SPHAGNACE^. 



tides, more rarely iu brackish ditclies, or i 

 upon decaying marine Alga?, 



The best distinctive marks of this species 

 are, the subacute extremities, combined 

 with the short filament and littoral habit. 



S. Jacohi. Filaments elongated, their ends 

 usually' attenuated ; ordinary cells subsphe- 

 rical; vesicular cells spherical; sporangia! 

 cells oblong or cj-lindrical. — Ralfs, I. c. pi. 8. 

 fig. 8; Eny.Bot. 2826. fig. 2. Forming thick, 

 bluish-green, gelatinous masses, fii'om which 

 the filaments issue in long rays. Fresh- 

 water. 



S. eladica (PI. 8. fig. 3). Dissepiments 

 conspicuous ; ordinary cells quadrate ; vesi- 

 cular cells eUiptic ; sporangial cells cjdiu- 

 drical, trmicate. — Ealfs, I. c. pi. 8. fig. 9. 

 Cylindrospenmim elonfjatum, Kiitz. Tub. 

 Phi/c. i. pi. 99. fig. 3. Forming a tender 

 stratum, of a deep bluish colour", in bogs. 



** Filaments moniliform; sporam/ia turyicl, 

 much broader than the ordinary cells. 



S. Broomeij Thwaites. Filaments elon- 

 gated ; ordinary cells suborbicular ; vesicu- 

 lar cells barrel-shaped or elliptic ; sporangial 

 cells elliptic, catenate. — Ralfs, /. c. pi. 7. 

 fig. 10. Forming a firmish bluish- or yel- 

 lowish-green stratimi in brackish ditches. 



*S'. Berkeleyana, Thwaites. Ordinary 

 cells spherical or slightly compressed ; vesi- 

 cular cells spheroidal, compressed, as broad 

 as the large, turgid-elliptic, sporangial cells. 

 — Ralfs, I. c, pi. 8. fig. 11. In brackish 

 ditches. 



<S'. Mooreana, Ralfs. Ordinary cells sub- 

 spherical; vesicular cells barrel-shaped, 

 much narrower than the large, broadly 

 elliptical sporangial cells. — Ralfs, /. c. pi. 8. 

 fig. 12. An Lish species. 



*** Dissepiments obscure ; cells longer than 

 broad. 



S. leptos2)erma (Kiitzing). Filaments 

 elongated, not constricted at the dissepi- 

 ments ; ordinary cells longer than broad, 

 confluent ; vesicular cells elliptic ; sporan- 

 gial cells linear. — Ralfs, /. c. pi. 8. fig. 13. 

 Cylindrosjjermuni leptospermum, Kiitzing, 

 Tab. Phyc. i. pi. 99. fig. 2. Forming large 

 shapeless gelatinous masses in still waters, 

 varying from deep green to yellowish green, 

 or, when the filaments are comparatively 

 few, nearly colourless. Distinguished espe- 

 cially by the " confluent ordinary cells with 

 obscure dissepiments." 



SPHAGNA'CE^.— A family of Clado- 

 cai-pous Mosses, of pecidiar habit, growing 



in bogs &c., distinguished especially by the 

 mode of branching, the structm-e of the 

 leaves, sporanges, and antheridia, and by 

 the absence of roots, except in the early 

 stages of growth. 



The stem of the Sphayna is composed of 

 three layers of cells, — a cortical, a medullary, 

 and an intermediate prosenchymatous layer, 

 which finally becomes somewhat woody. 

 The primary axis is indefinite in its gro'wth ; 

 the lateral axes, steiile or fertile, are an- 

 nual. The secondary axes are fascicidate ; 

 and being pendent or recurved upon the 

 stem, they fulfil in some measm-e the func- 

 tion of roots. The leaves are remarkable for 

 their cellular sti'ucture, being composed of 

 two kinds of cells — namely, narrow and 

 elongated cells filled with chlorophyll, con- 

 joined into a kind of network, the meshes 

 of which are occupied by large hyaline cells. 

 The hyaline cells contain, in all but one 

 exotic species, a spiral or annular secondary 

 deposit (PI. 48. fig. 25) characteristic of 

 this family. These large cells also become 

 opened by regidar circular pores at a certain 

 stage of growth. 



The inflorescence is monoecious or di- 

 oecious. The antheridia are produced singly 

 in the axils of perigonial leaves at the club- 

 shaped tips of short branches. They are 

 pedicellate and roundish, like those of the 

 Liverworts ; they produce biciliated sper- 

 matozoids. The archegonia are found about 

 four together, sessile, in a tuft of perichaj- 

 tial leaves occupying the axis of a fascicle 

 of branches, the receptacle subsequently 

 elongating into a peduncle, bearing a glo- 

 btdar capsule, entirely surrounded by the 

 calyptra. The cah-ptra is ruptured near the 

 middle, the lower part persistent and con- 

 tinuous with the fleshy vaginule, within 

 which the capsule. is seated on a bulb-like 

 pedicel : peristome none ; operculum flattish, 

 thrown oft' with elasticity. Spore-sac 

 wanting ; columella short, not reaching the 

 mouth of the capsule. Spores apparently of 

 two kinds, some enclosed four together in 

 parent cells, others smaller, sixteen in one 

 parent cell : the former fertile, the latter 

 sterile, occming either together or in di- 

 stinct capsules. The spores in germinating 

 produce a Marchantioid body, very dillerent 

 from the confervoid mass of ordinary mosses. 



British Genus. 

 Sphaymim, Dill. Character that of the 

 order. Nine species occiu- in Britain, some 

 common on every bog, distinguished by 



