150 



MUSCINE^E 



ORDER 2. PHASCACE^E. 



In the small order of Phascaceae the roundish sporange dehisces 

 neither by the detachment of an opercule nor by longitudinal slits, but 

 decays to allow of the escape of the spores ; the calypter is ruptured 

 laterally without being raised up as a cap ; the columel is sometimes 

 wanting. According to Leitgeb, 

 Archidium (Brid.) resembles the 

 Hepaticse more closely than the 

 Bryacese in the processes which 

 lead to the formation of the 

 spores, especially in the differ- 

 entiation of the archespore into 

 spore-mother-cells which are 



FIG. 121. E^>hemerntm serratum Hampe ; 

 mature plant with persistent protoneme 

 (magnified). (After Luerssen.) 



FIG. 122. Pleuridium subulatum Rabenh. 

 sporange (magnified). (After Luerssen. 



irregularly interspersed among cells that remain sterile. The spore- 

 mother-cells do not number more than from one to seven in each spo- 

 range ; in each of them four spores are formed tetrahedrally. 



The Phascaceae are caespitose in their habit \ the protoneme persists 

 until the maturity of the sporogone. Principal genera : Phascum (L.), 

 Archidium (Brid.), Ephemerum (Hpe.), Pleuridium (Brid.). 



LITERATURE. 



Leitgeb Sitzber. Akad. Wiss. Wien, 1 880, p. 447. 

 Miiller Pringsheim's Jahrb. wiss. Bot., 1867, p. 237. 



ORDER 3. 



The Andreaeacese constitute a small order of mosses, comprising the 

 single genus Andreaea (Ehrh.), characterised by the absence of an oper- 

 cule to the sporange, which opens by four, or very rarely eight, longi- 

 tudinal slits, not reaching either to the base or the apex of the capsule. 



