'M^ 



MUSCINEM. 



two, but this bipartition is usually not completed, the division into four taking 

 place at once. The preparation for the formation of spores takes place simulta- 

 neously everywhere within the same capsule. The ripe spores are roundish or 

 tetrahedral, surrounded by a thin finely granulated exospore, which is of a yellowish, 

 brownish, or purple colour. Besides protoplasm, they contain chlorophyll and 

 oil. In Archidium, where only sixteen are formed in each capsule, they are 

 about \ mm. in size, in the highly developed Dawsonia scarcely -^-^ mm. (Schimper). 

 When kept dry the spores often retain their power of germination for a long time, 

 but when moist they frequently germinate after a few days, those of Sphagnum 

 after two or three months. 



The time necessary for the formation of the sporogonium varies greatly in the 

 different species, but is usually very long in comparison with the small size of the 



Fig. 259. — Sphagituvi acutifolhtnt ; the flat protonema/r with a young leafy 

 stem m (after Schimper, X about 20). 



Fig. ■zej^.—Sphag7ium acutifolium ; ^ a large 

 spore, seen from the apex ; B a small spore ; C a 

 protonema n n' resulting from the spore s ; pr 

 rudiments of young plants (after Schimper). 



body concerned. The Pottieae blossom in summer, and ripen their spores in the 

 winter ; the Funarieae are perennially in blossom, and have constantly sporogonia in 

 all stages of development, each occupying for its completion probably 2 to 3 months ; 

 Phascum cuspidaium developes in the autumn from its perennial underground proto- 

 nema, and ripens its spores in a few weeks before the winter. The bog Hypna, on 

 the other hand (ZT. gi'ganteum, cordifolium, cuspidatum, miens, &c.), blossom in August 

 and September, and ripen their spores in July of the next year ; they often require 

 ten months for the development of their sporogonia. H. cupressiforme bears in 

 autumn at the same time sexual organs and ripe spores, and hence requires one year. 



