GROUP II. BRYOPHYTA : MUSCI. 



345 



X J- 



Fm. 210. Sporogoninm of Funaria hyyromelrica. A, s seta; b capsule; e calyptra (x6). 

 15 Section of a half-developed capsule (x 10): c columella ; archesporium ; I air-cavity; 

 d sub-opercular tissue ; p peristome. C Apical portion of the same capsule ( x 40) j d oper- 

 culum; id sub-opercular tissue; ap outer peristome; tp inner perisiome ; r ring; I air- 

 fpace; c coliimel'a ; s spore-sac. 



variations in their moisture, that the splitting off of the operculum is 

 effected. 



The Stegocarpse are classified as follows : 



Sub-tribe AciWCARPM : archegonia terminal on 

 the main shoots ; but ths sporogonia are some- 

 times apparently lateral in consequence of the 

 growth of lateral branches (innovations) which 

 force the apex: of the main shoot to the side. 



Sub-Tribe PLEUROCARP& .- archegonia (and 

 subsequently the sporogonia) borne terminally 

 on short lateral branches. 



The following are among the more familiar 

 species of acrocarpous Mosses : 



Dicranuni scoparium, with sickle-shaped leaves, 

 is common in woods. Leucobryum glaucum has 

 leaves consisting of several layers of cells, which. 

 resemble those of Sphagnum in their structure ; 

 it occurs in Pine-woods and on moors. Cerato- 

 don purpureus, with a red seta and a short stem, 

 is very common in various localities. Barbula 

 muralis grows in patches on walls and rocks; 

 the midrib of the leaves is prolonged into a 

 hair, so that the patches of Moss look greyish. 

 Tetraphis pellucida has bright green leaves ; it 

 u;rows on decayed tree-trunks, and bears gemmae 

 of peculiar form. Grimmia pulvinata occurs on 

 walls and stones in round greyish-green patches 5 

 the capsules have very short setae. Orthotrichum 

 affine and other species have also shortly-stalked 

 capsules, and are common on tree, Funaria ^< 

 hyyrometrica (Figs. 208, 210) has an oblique, jDear- c calyptra. 



FIG. 211. Two plants of 

 P'tyMch /onnowtm bear- 



