IIEPATICACE.E. 



[ 320 ] 



HEPATICACEiE. 



which represent the anthers of flowering 

 plants are called antheridia, those which re- 

 present the ovules, and produce the spore- 

 cases, are called archegonia or lyistillidia. 

 The antheridia are small globular or oval 

 bodies, more or less stalked, which in the 

 Jungermannieae are composed of a double 

 layer of cells forming a membranous sac, 

 which, when ripe, bursts and discharges 

 numerous minute globular cellules, each of 

 which again bursts and discharges an ex- 

 tremely small filament, which moves about 

 actively in water (figs. 327 & 328). These 



Fig. 326. 



Fig. 327, 



Fig. 328. 



Haplomitrium Hookeri. 

 Fig. 326. Axillary antheridia. Magn. 30 diams. 

 Fig. 327. Fragment of wall of antheridia ; the reniform 

 loose cells belong to the inner laj^er. Magn. 200 diams. 

 Fig. 328. Spermatozoids from ditto. Magn. 200 diams. 



organs mostly occur in the same situations 

 as the archegonia, and in some of the fron- 

 dose forms, such as Anthoceros, Riccia, 

 Fimbriaria (fig. 322), &c., they are imbedded 



Fig. 329. Fig. 330. Fig. 331. 



Marchantia polymorpha. 



Archegonia in various stages. 



Magnified 100 diameters. 



in the substance of the frond ; in others, as 

 in Marchantia, they are immersed in the 

 upper part of special male stalked receptacles 

 (see Marchantia) ; in the leafy forms, 

 they are free in the axils of the leaves (fig. 

 327). 



The archegonia or pistillidia are likewise 

 developed in various places, indicated here- 

 after in the tabular view of the families. 

 They consist of a kind of flask-shaped cellu- 

 lar case (figs. 329 to 331), enclosing at first a 

 single cell (embryonal cell), which subse- 

 quently grows into a sporange, apparently 

 after one or more of the spiral filaments of 

 the antherids have come in contact with it, 

 by passing into the neck of the flask-shaped 

 sac (epigone). The embryonal cell becomes 

 increased by cell-division into a globular 

 cellular mass, which acquires various forms 

 in the difi'erent genera and families. The 

 epigone enlarges for a long time with the 

 growing capsule, completely enclosing it 

 (fig. 332), but after a time the latter bursts 



Fig. 332. 



Haplomitrium Hookeri. 



Young sporange enclosed in the epigone. 



Magnified 20 diameters. 



through the top of the epigone, which thus 

 forms a kind of sheath round the base of the 

 sporange or its stalk, and is called the vagi- 

 nule. The epigone may tear irregularly, so 

 as to form an irregular vaginule or calyx, or 

 regularly, so as to present a circle of teeth ; 

 or it may be slit horizontally in a circle, and 

 half of it carried up by the sporange, which 

 it thus surmounts as a hood or calyptra. 

 This epigone is sometimes surrounded by 

 another envelope called the perigone. This 

 originates at a later period and in a diff'erent 

 way, since it gradually springs up as a cir- 

 cular sheath around the base of the epigone, 

 and by continued growth comes to surround 

 it as a kind of cup, like the corolla of a 

 flower (fig. 324). In Marchantia, only one 

 archegone is found in each perigone ; the 



