CRTPTOGAMOUS OK FLOWEKLESS PLANTS. 



503 



peristome), which are always some, multiple of four : those of the 

 outer row are called teeth, of the inner, cilia. The spores which fill 

 the cavity commonly appear like an impalpable greenish powder. 

 The pedicel continued through the capsule forms the columella : en- 

 larged under the capsule it sometimes forms an apophysis. The 



calyptra separating early at its base is carried up on the apex of the 

 capsule ; if it splits on one side, it is hood-shaped or cuculliform, if 

 not, it is mitre-shaped or m,itriform. The particular structure of all 

 our genera of Mosses, and of the following order, is illustrated in 

 the plates of the Manual of the Botany of the Northern United 

 States ; to which the student is referred for details. 



973. Ord. HepatiCSB {Liverworts). Frondose or Moss-like plants, 

 of a loose cellular texture, usually procumbent and emitting rootlets 

 from beneath ; the calyptra not separating from the base, but usually 

 rupturing at the apex ; the sporangium or capsule not opening by a 



FIG. 1300. Mnium cuspidatum. 1301. The calyptra detached from the spore-case. 1302. 

 Magnified spore-case, from which the lid or operculum, 1303, has been removed, showing the 

 peristome. 1304. A portion of the annulus or ring under the lid, more magnified. 1305. A 

 portion of the Outer and inner peristome, highly magnified. 1306. The so-called flowers in a 

 young state, consisting of the pistillidia 5 , and the antheridia (^, with some cellular jointed 

 threads intermixed ; the involucral leaves cut away. 1307. One of the antheridia mor* magni- 

 fied (with some accompanying cellular threads), opening at the apex, and discharging the con- 

 tents. 1308. Simple peristome of Splachnum ; the teeth united in pairs. 1309. Double peris- 

 tome of Hypnum ; the exterior spreading. 1310. Physcomitrium (Gymnostomum) pyriforme. 

 1311. Its calyptra, detached from, 1312, the theca. 1313. The lid removed from the orifice, 

 which is destitute of a peristome. 



