224 IMPERFECT PLANTS, 



of an extinguisher, Fig. 129 a. In this state it has been 

 called a calyx by some botanists, and by others a corol- 

 la ; but its resemblance to either is so slight, as scarcely 

 to justify the terms. It is more generally known, how- 

 ever, by the appellation of the Calyptra, or veil ; a 

 term sufficiently expressive, of at least part of its func- 

 tions, masking as it does a globular or urn-shaped ves- 

 sel, which is the capsule of the Mosses. In some spe- 

 cies this capsule is sessile, but in most cases it is eleva- 

 ted upon a fine slender foot-stalk ; and is erect or droop- 

 ing, smooth or striated ; being in a young state green 

 or white, but at maturity becoming yellow, or red, or 

 brown. The mouth of the capsule is externally cover- 

 ed with a lid, [operculum) Fig. 129 d, assuming in dif- 

 ferent species a variety of forms, and detaching itself 

 horizontally when ripe. When this lid is removed, the 

 mouth of the capsule is seen, invested with a fringe 

 (peristomium) Fig. 118, which is usually double, occa- 

 sionally single, and very rarely wanting ; Fig. 129 c. 

 The number of the teeth of this fringe, though varia- 

 ble in different genera, is uniform in the same ; and it 

 is worthy of observation, that this number is in all ca- 

 ses a multiplicate of 4, being 4, 8, 16, 32, and 64. 

 Within the urn, there is a slender column, which pass- 

 es through its whole extent, and perforates both the lid 

 and the veil. This organ was regarded by Hedwig as 

 the style of the Mosses. As the urn and column are 

 concentric, there is an intermediate and cylindrical 

 cavity, filled with a powder usually brown or yellow, 

 and sometimes dotted or prickly. By sowing this pow- 

 der, Hedwig reared a crop of young Mosses, in all 

 respects similar to the parent plants ; thus proving be- 

 yond the possibility of a doubt, the nature of the dust 

 which he planted. 



