CELLULAEES, OR CELLULAR PLANTS. G9 



fined to the lower extremities of the axis of growth, and the 

 fructification is terminal, or comes out at the summit of the 

 branches. Such mosses are evidently the higher represent- 

 atives of the family. This is well seen in the genus Cli- 

 maeium dendroides, which has an arborescent growth, and 

 presents the appearance of a beautiful tree in miniature. 



88. Such mosses as have lateral fruit are called Pleuro- 

 carpi (n:>,6Dpa side, and xa^nbi fruit) ; those in which the fruit is 

 terminal are called Acrocarpi (axpa summit, and xaprtos fruit). 



89. If we carefully examine a moss in fructification, we 

 shall soon see a number of urn-shaped bodies, sporangia 

 (ffftopa a spore, and ayyoj a vessel), supported on capillary 

 peduncles, which rise from amidst the foliage. Surrounding 

 the base of the peduncle, a number of leaves will be perceived 

 somewhat different in exterior configuration from the rest, 

 which serve as a kind of calyx, inclosing the fructification 

 in the earlier stages of its growth, and which are called the 

 perichsetial leaves (jii^l around, aod ;{;<*i'*'«? a bristle). 



90. The sporangia are at first covered by a membranaceous 

 body called a calyptra (xaXvH'tfa,, a covering), and enveloped 

 in the perichsetial leaves in the axilla or summit of the 

 branches. When first elevated above the perichsetial leaves, 

 nothing is apparent but a number of stiff bristle-like pro- 

 cesses, each rising from its own perichseth. -From this, how- 

 ever, we must except Dicranum undulatum, which has several 

 setas originating in the same perichaeth, and the fruit of which 

 appears in clusters. The young fruit of mosses is called, for 

 this reason, setsB (seta, a bristle). As the setse of mosses 

 elongate, the reproductive cells at their summit begin to 



