64 



BRYACE^. 



[ACBOGENS. 



Order XX. BRYACEiE.— Urnmosses. 



Musci Ju^s Gen 10 (1789) • Hedwin Descr. et Adumb. (1787-1797) ; Bridcl Muscolog. rMeMwrum 

 ''" 1797^803, iid J IJ'^ Frondos. (1801) -Palisot Prodrome d.s5et 6 Fa- ^r^'J^«- 



gam. (1805> ; Bridal Suppl. (1806-1819) ; Weber Tabul. Muse. Frondos. {1813) ; DC. Fl.p.2^SS. 

 (1815 ; T. F. L. Nee de Muscor. Propap. (1818); Hooker and Taylor Muse Brit. {1818); 

 Hooker, Musei Exotici aSlS-1820) ; Agardh Aphor. 105. (1822); ^'•^^'^«'' ««5 f '-"^"o ^" ^;^- 

 Trans. '^. 109. ^c. (1822) ; Nees v. Esenbeck, Hornschueh <^'^dmrm Bryolog^^^^^^^^^^ Grev. 



Ft. Edin. xm.{182i); Ad. Brongn. in Diet. Class. U. 248. (1827) -Hooker. Brit. Fl. 1. 459. 

 (1830).-Bryace£e, Ed. pr. (1836) ; Endl. Gen. xxiv. - Sphagnacese, Endl. Gen. xxiu. 



jyiAGyosis-Spore-cases valvular, with an operculum, without elaters. 

 Erect or creeping, terrestrial or aquatic, cellular plants, having a distinct axis of 

 growth, destitute of a vascular system, and covered with minute mibricated, entire, or 

 serrated leaves. Reproductive organs of two kmds, ^'iz. 1 . Antheridia, which are axillary, 



cylmdrical or lusiiorm 

 12 3 * stalked sacs, containing 



a multitude of spherical 

 or oval particles emitted 

 upon the application of 

 water, and coiled up 

 bodies which move in 

 water ^^•ith actiA"it3'; 2 

 Pistillidia, or flask-hke 

 bodies inclosed within a 

 convolute bract, which is 

 eventually carried up up- 

 on the point of the spore- 

 case. Spore-case.s, or 

 ripened pistillidia, hollow 

 lu'iilike vessels, seated up- 

 on a seta or stalk, covered 

 by a membranous calyp- 

 tra , closed by a lid or oper- 

 culum, beneath which are 

 one or more I'ows of cel- 

 lular rigid processes, call- 

 ed collectively the peri- 

 stome, and separately 

 teeth, which are always 

 some multiple of four, 

 and combined in various degi'ees ; the centre of the theea is occupied by an axis or colu- 

 mella, and the space between it and the sides of the theca is filled with sporules. Spo- 

 rules in germination protruding confervoid filaments, which afterwards ramify, and 

 form an axis of growth at the point of the ramifications. 



These little plants, which form one of the most mteresting departments of Crypto- 

 gamic Botany, are distinctly separated from all the pi'evious tribes by the pecuUar 

 structure of their reproductive organs, in which they resemble no others, except the 

 Scalemosses, whose approach, however, is more apparent than real. In their organs 

 of vecfetation they are strikmgly similar to many Clubmosses, to which, perhaps, an 

 approach is made by Sphagnum, whose spore-case has no peristome, on which account, 

 indeed, that genus is regarded as a distinct Natural Order by Endlicher, 



For a long time Urnmosses were considered to be destitute of stomates ; but first 

 Treviranus, and afterwards Valentine, distinctly proved those organs to be present ; (Linn. 

 Trans. 18, 239). In addition to such apertm-es, some of the cells of certain species of 

 Sphagnum are pierced with large round openmgs ; and Roeper has observed, that such 

 perforated cells are the habitation of the animalcule called Rotifer vulgaris. (Flora, 

 1838, p. 17.) ]Mohl has observed similar openings in the cells of Leucobryum ATilgare, 

 (Dicranum giaucum,) and Octoblepharum albidum ; he thinks they are fonned subse- 

 quently to the construction of the cells. Ann. Sc. N. s. xiii. 108. Schleiden confirms 



Fig. XLV 



Ficr. XLV. —1. Peristome of Tortula ruralis ; 2. Theca of Ceratodon purpureus ; 3. Supposed repre- 

 sentatives of sexual organs in Meesia longiseta ; 4. BrjTim roseum ; 5. Peristome of Octoblepharum 

 albidum ; 6. Apophysis and theca of Splachunm luteum. 



