MOSSES 455 



P. commune has sixty-four teeth ; P. aloides, thirty-two ; and several 

 other species only sixteen. 



The male plants of P. commune have the star-shaped heads to which 

 reference has been made. 



The spore-cases of this species ripen in June and July ; those of P. aloides 

 in winter. 



Catharinea undulata (another member of the Polytnchacecs) is not so 

 bristly in appearance ; the capsule is longer, and the lid is as long as the 

 capsule. It is found on clayey or sandy soil, and ripens in autumn and winter. 



Tetraphis pellucida, about | inch high, found on turfy banks and rotten 

 tree stumps, has a four-toothed capsule. Some of the leaves at the end of the 

 stems form a minute cup containing a green, dust-like mass of gemmae. 



Dicranum scoparium (Broom Fork Moss) is one of the largest species, 

 found on shady banks, heaths, and in woods. The capsule is yellow or red- 

 dish brown, and the peristome bright red. The cells of the young leaves 

 contain, besides chlorophyll, certain round oil globules, two or three in a 

 cell ; these are a means of identification. 



Ceratodon purpureus, | to 3 inches in height, is recognized under the micro- 

 scope by the colour of its teeth dark purple at the base, gradually changing 

 through red, orange, and yellow to a pearly transparency at the tip. 



Tortula muralis is a typical species of the TORTULACE.E, found on brick 

 walls, generally on the cement. It has a twisted peristome, hence its name 

 Wall Screw Moss. The central rib of the leaf projects into a fine bristle- 

 like hair. Most of the species have long, corrugated capsules, dark purple 

 in colour, and pink peristomes of twisted teeth. 



Funaria hygrometrica (Common Cord Moss) has fruit-stalks which twist 

 up when dry ; when breathed upon, they uncurl. It is frequently found 

 growing on patches of ground which have been burnt. 



In Mnium hornum, which is very common, the capsules are to be found 

 in May and June : orange or reddish brown, with bright red mouths. There 

 is only one capsule to each plant ; but in Mnium undulatum ten, and some- 

 times eleven and twelve capsules, even more brightly coloured, will be found 

 growing from each stem. 



The SPLACHNACE.E are recognized by their habit of growing on decayed 

 animal matter or dung ; the BARTRAMIACE/E, by their rounded capsules. 



