8 Illinois State Lnhoratorij of Natural Historij. 



gradually dies away; the branches thus become independent 

 plants by a sort of compulsory self-division. By this method 

 large areas become covered with a single species without the 

 production of spores. 



Gemmge (Lat. gemma, a bud) are variously produced in 

 different genera. In some (Madotheca) they are simply cells 

 detached from the margin of the leaves; in others (Marchan- 

 tia) they are produced in broad cup-shaped receptacles on the 

 upper side of the th alius, looking like miniature bird's nests 

 with their included eggs; in other genera the receptacle may 

 be flask-shaped (Blasia), or crescent-shaped (Lunularia). The 

 last-named species may be seen in almost any greenhouse, where 

 it has been introduced from Europe, and the crescent-shaped 

 gemmae cups are found on nearly every plant. Many species 

 produce^ no gemmse. 



Less commonly the Hepaticae multiply by runners, a pecu- 

 liar form of which is termed ^ fiagellum (Lat. a lash). Tubers, 

 so called, were once supposed to form a fourth method of re- 

 production, but these " endogenous gemmae " have been found 

 to be produced from filaments of Nostoc. They are most com- 

 mon in some species of Anthoceros. 



Sexual Organs. Two kinds are present^ known respect- 

 ively as arrhegonia (Grr. archa, beginning, and gonos^ seed), 

 analogous to pistils, and antheridia (Lat. anthera, an anther, 

 and Gr. eidos^ form), analogous to stamens. The relative posi- 

 tion of these organs on the plant varies greatly in different 

 genera. When the sexual organs are in the same cluster the 

 term syncecious (Gr. sun, together, and oihia^ house) is used; 

 this form, however, rarely, if ever, occurs among the hepatics. 

 When the antheridia are situated in the axils of bracts near the 

 archegonia, or when (as in Fossomhfonia ) both organs are 

 naked on the dorsal surface of the same stem, the relation is 

 said to be paroecious (Gr. ^9arr/^ beside, and oikia). When the 

 antheridia occur in a separate receptacle on the same plant as 

 the archegonia, the plant is monoecious; the same arrangement, 

 but with the sexes on separate plants, is the dioecious relation. 

 In some species one or more relations exist, apparently with- 

 out special reason. 



Antheridium. The male organ is usually globose or oval 



