HEPATIC^. 



[ 389 ] 



HEPATIC^E. 



perichsete is always developed before the 

 archegones it encloses, while the perigone, 

 as already stated, grows up round the arche- 

 gone during its development into a sporange, 

 being absent at the time of the first appear- 

 ance of that organ. In fig. 320 the base of 

 the pedicel is seen to rise out of a toothed 

 vaginule (calyx or epigone), which is enclosed 

 in a tubular perigone, outside of which are 

 two bilobed perichaetial leaves. 



The sporange developed from the embry- 

 onal cell of the archegone varies much in 

 its perfect condition. In Jungermanniese it 

 is mostly an oval body borne on the extre- 

 mity of a delicate thread-like stalk spring- 

 ing out of the ihiginule (fig. 320). The oval 

 body splits down from the summit, when 

 ripe, into four valves, which spread open 

 more or less in the form of a cross (figs. 

 320-1), or bursts irregularly. The cells of 

 the valves exhibit very elegant spiral- 

 fibrous structure, like that of the walls of 

 anthers (see SPIRAL STRUCTURES). This 

 kind of sporange discharges minute spores 

 (see SPORES) and elaters, slender tubular 

 cells containing a spiral filament (PI. 40. 

 fig. 38), both forming very interesting 

 microscopic objects. 



In the different frondose forms the spo- 

 ranges present very varied conditions. The 

 archegones of ANTHOCEROS send up a fili- 

 form sporange, which is two-valved and 

 contains a columella (fig. 24, p. 58). In 

 TARGIONIA and some others the capsule is 

 almost sessile, and bursts irregularly. In 

 RICCIA, where the archegones are imbedded 

 in the frond, the sporange is a sessile globose 

 body, with the calyptra adherent, never 

 bursting regularly, but emitting the spores 

 by decay. In SPHJERO CARPUS, also, the 

 calyptra is permanent as a cellular sac, in- 

 side of which the sporange ripens into an 

 indehiscent globular body, emitting the 

 spores only by decay. In Marchantia, Fe- 

 gatella,Lunularict) 6rrtmo&&i,&c.,the arche- 

 gones are produced on fleshy receptacles 

 elevated upon stalks, and the sporanges 

 are formed on the underside of these 

 receptacles (fig. 219. {>. 317, figs. 330, 333, 

 335), which are of varied forms, &c. The 

 sporanges on these either burst by valves 

 (fig. 331), or by circumscissile dehiscence 

 throw off a lid, as in Fimbriaria (fig. 335). 



The frondose forms do not all produce 

 elaters, and have not all the spiral fibres in 

 the cells of their walls. The exceptions 

 are the Ricciese; and the elaters of Antho- 

 ceros are rudimentary. In Marchantia the 



Fig. 329. 



Fig. 330. 



Fig. 331. 



Lanularia vulgaris. 

 Fig. 329. Section of a receptacle, unripe. 

 Fig. 330. More advanced sporange, emerged from the 



epigone. 

 Fig. 331. A burst sporange. 



Magnified 20 diameters. 



Fig. 332. Fig. 333. 



Grimaldia barbifrons. 



Fig. 332. Fertile plant. Magn. 2 diams. 



Fig. 333. Section of the receptacle, with an abortive 

 archegone on the left side, and a half-ripe sporange still 

 enclosed in the epigone on the right. Magn. 20 diams. 



. 334. 



Fig. 335. 



Fimbriaria tenella. 



Fig. 334. Eeceptacles with closed epigones. Magn 

 10 diams. 



Fig. 335. Two perigones, one with the epigone closed, 

 the other with the teeth of the epigone open, showing 

 the bursting sporange. Magn. 20 diams. 



elaters are highly developed (PI. 40. figs. 

 36, 37), also the spiral tissue of the valves 



