3ROUP II. BRYOPHYTA: HEPATIC^. 337 



vegetative and a reproductive portion, the gametopliore : the gametophore is a 

 branch (or a branch- system) bearing a terminal receptacle, in which either the 

 male (antheridiophore) or the female (archegoniophore) organs are developed. 



In the simpler forms (e.g. Sauteria, Fimbriaria, Duvalia, Grimaldia, Reboulia) 

 the archegoniophore is simple, that is unbranched ; the stalk presents a single 

 furrow which represents the ventral surface of the shoot. In Lunularia the 

 stalk is simple, but the receptacle itself is branched, presenting four groups 

 of archegonia, each group corresponding to one of the coherent branches of 

 which the receptacle consists ; hence the archegoniophore is compound. In 

 Marchantia, Preissia, and Dumortiera, the stalk has two ventral furrows, 

 showing that it consists of the two coherent branches of the first dichotomy. 

 The receptacle itself is repeatedly branched : thus in Preissia there are four 

 groups of archegonia, corresponding to four branches ; in Marchantia and 

 Dumortiera there are eight. The receptacle is more or less distinctly lobed, 



FIG. 210. A Portion of a plant of MarcUantia polymorplia (t), with antheridiophores. 

 B Portion of a plant with a cupule containing gemmae; v v apices of the two branches. 

 (After Sachs.) C An archegouiophore with a doubly furrowed (r) stalk t, bearing a 

 terminal branched receptacle of which s is one of the rajs ; h perichaetium ; fc sporogonia. 



thus showing its compound nature; each group of arcbegonia is situated be- 

 tween the bases of two adjacent lobes. The complete elongation of the stalk 

 does not take place until the archegonia are fully developed, or even until one 

 of them has been fertilised. 



It is only in a few of the higher Marchantieae that there is a highly de- 

 veloped autheridiophore. In the lowest forms the antheridia are developed 

 in dorsal groups, the formation of which does not arrest the further apical 

 growth of the branch ; in Grimaldia and Keboulia, the formation of the groups 

 of antheridia causes temporary arrest of apical growth ; in Luuularia and 

 Duvalia the formation of a group of antheridia permanently arrests the apical 

 growth of the branch, the group being therefore terminal. In Fegatella, Preissia, 

 Marchantia, and Dumortiera, a definite terminal receptacle is formed; it is 

 discoid in form, and (except Fegatella) it is elevated on a special artheridio- 

 phore ; it is compound, having several growing points, each of which gives 



V. S. B. Z 



