BARLEY. 



[ 91 ] 



BARTRAMIOEDELE. 



tearing of these peridermal layers. Here, 

 therefore, the periderm is produced from 

 the cellular envelope. 



In the Lirne (Tilia\ the Oak (Q.Bobnr), 

 and other trees, a similar production of 

 peridermal layers within the liber takes 

 place ; but the layers remain in situ for a 

 long time, and fall away irregularly, often 

 persisting for a considerable number of 

 years as rugged, many-layered scales. 



In many of the Coniferse (such as the 

 Scotch Fir and Larch), the peridermal struc- 

 ture is in like manner developed from the 

 cellular envelope ; here, however, the cells 

 are not tabular, but parenchymatous, and 

 multiply and enlarge so as to form a thick 

 layer of cork-like tissue, which loses all 

 relation with the medullary rays. The tur- 

 pentine-canals and liber-fibres, engaged in 

 this corky periderm, become disturbed and 

 displaced by its irregular growth. 



In some" plants, such as the Vine, the 

 Honeysuckle, &c., the bark is always stringy, 

 which arises from the formation of each 

 annual layer of liber being followed imme- 

 diately by the drying-up, and soon by the 

 destruction, of the layers of the preceding 

 year, so that no proper periderm of suberous 

 or cellular layers exists here after the first 

 year. The same takes place in the third or 

 fourth year in Clematis. 



The scales, plates, and rings of bark 

 thrown off, form the rhitidome of some 

 authors. 



The inner layers of the bark are especially 

 distinguished by the presence of laticif erous 

 canals in those plants in which that tissue 

 exists ; these are said by Schacht to be in 

 many cases a modification of the liber-tissue. 

 Further particulars are given on this head 

 under LIBER, where also the intimate struc- 

 ture of the liber will be explained. See also 

 LENTICELS and CORK. 



BIBL. Henfrey, Bot. (Masters); Mohl, 

 Vermischt. Schrift. 1845, p. 212 ; Hanstein, 

 JBau d. Baumrinde, Berlin, 1853 ; Schacht, 

 Pflanzenzelle, p. 237 ; Sanio, Pringsheim's 

 Jahrb. ii. 39 ; Sachs, Bot. 107. 



BARLEY. One of the important cereal 

 grains,f urnished by the Hordeum sativum and 

 its varieties (Monocot. Plants, N. 0. Grami- 

 nacese). The starch of the albumen of the 

 seeds has a form somewhat resembling that 

 of wheat, but it may be distinguished un- 

 der the microscope (PI. 46. fig. ) ; and the 

 small starch-grains are more numerous and 

 smaller than in wheat or rye, and many of 

 them are in active molecular motion when 



immersed in water. (See STARCH.) Pearl- 

 barley is obtained by a peculiar mode of 

 grinding, by which the outer coat or shell 

 of the grain is removed. 



BARTRA'ML^, Hedw. A genus of 

 Bartramiaceous Mosses, containing several 

 common species. B. pomiformis, with its 

 apple-like capsules, is common on dry sandy 

 banks. 



BIBL. Wilson, Bryol. Brit. p. 277. 



BARTRAMIA'CE^E. A tribe of Bar- 

 tramioidese (operculate Apocarpous Mosses) 

 containing several genera. British genera : 



Conostomum. Calyptra dimidiate. Pe- 

 ristoine simple; teeth sixteen, lanceolate, 

 equidistant ; erect when wet or dry, densely 

 and nodosely tuberculated, with a median 

 line, connate in pairs at their apices, and 

 coherent into an oblique closed cone. 



Bartramia. Calyptra dimidiate. Peri- 

 stome either absent, simple, or double. Ex- 

 ternal, of sixteen lanceolate, smooth, tuber- 

 culate teeth, with a median line or sometimes 



Fig. 52. 



Bartramia marchica. 



Magnified fragment of peri- 



stome. 



separating in the 

 middle, erect when 

 wetted, incurved 

 when dry, red. In- 

 ternal : a mem- 

 brane with sixteen 

 folds, produced in- 

 to sixteen lanceo- 

 late, keeled, broad 

 teeth, ultimately 

 split into two di- 

 vergent articu- 

 lated lobes, with 

 one to three cilia 

 interposed or none 

 (fig. 52). 



Catascopntm. Calyptra hood-shaped, 

 smallish. Peristome simple ; teeth sixteen, 

 lanceolate, very short, truncate-lanceolate, 

 differing in form, unequal, transversely arti- 

 culated, with a median line, whitish, rugu- 

 lose, rigid and suberect. Capsule inclined on 

 the collum, globose, small, discelioid, shi- 

 ning-brown, and ultimately growing black, 

 thick-skinned, almost horny, without an 

 annulus, smooth. 



BARTRAMLD'ULA, Br. and Sch. (Bar- 

 tramia, Miiller). A genus of Mosses sepa- 

 rated from Bartramia by some authors on 

 account of the smooth capsule and absence 

 of a peristome. 



BIBL. Wilson, Bryol. Brit. p. 276. 



BARTRAMIOIDE^E. A family of 

 operculated Acrocarpous Mosses, of cespitose 

 habit and varying size. Leaves very varied 



