HEPATICACE^E. 



[ 321 ] 



HEPATICACE.E. 



perigones of Jungermanniese always enclose 

 several, but only one is developed into a 

 sporange. In some kinds, as Sarcoscyphus, 

 there are always several archegones in a 

 perigone, and two or three produce sporanges. 

 Sometimes the archegones, with or without 

 perigones, are solitary ; more frequently they 

 are in groups. Whether solitary or grouped, 

 they may have a further envelope composed 

 of slightly modified leaves, free or confluent 

 together; these are the pericheetial leaves, 

 and constitute the perichcete. When both 

 perichate and perigone exist, it is easy to 

 determine which is which, but when only 

 one exists, the history of development alone 

 gives the key ; the perichaete is always de- 

 veloped before the archegones it encloses, 

 while the perigone, as already stated, grows 

 up round the archegone during its develop- 

 ment into a sporange, being absent at the 

 time of the first appearance of that organ. In 

 fig. 324 the base of the pedicel is seen to rise 

 out of a toothed vaginule (calyx or epigone}, 

 which is enclosed in a tubular perigone, out- 

 side 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 springing 

 out of the vaginule (fig. 324). 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. 324-5). 

 The cells of these 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. 32. fig. 38), 

 both forming very interesting microscopic 

 objects. 



In the different frondose forms the sporanges 

 present very varied conditions. The arche- 

 gones of ANTHOCEROS send up a filiform 

 sporange, which is two-valved and contains 

 a columella (fig. 26, p. 49). 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 regu- 

 larly, but emitting the spores by decay. In 

 SPH^ROCARPUS, also, the calyptra is per- 

 manent as a cellular sac, inside of which the 

 sporange ripens into an indehiscent globular 

 body, emitting the spores only by decay. 



In Marchantia, Fegatella, Lunularia, Gri- 

 Fig. 333. Fig. 334. 



Lunularia vulgaris. 



Fig. 333. Section of a receptacle, unripe. 

 Fig. 334. More advanced sporange, emerged from the 



epigone. 

 Fig. 335. A burst sporange. 



Magnified 20 diameters. 



maldia, &c., the archegones are produced on 

 fleshy receptacles elevated upon stalks, and 



Fig. 336. Fig. 337. 



|\ 



Grimaldia barbifrons. 



Fig. 336. Fertile plant. Magn. 2 diams. 



Fig. 337. 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. 



Fig. 338. 



Fig. 339. 



Fimbriaria tenella. 

 Fig. 338. Receptacles with closed epigones. Magn. 10 



diams. 



Fig. 33Q. Two perigones, one with the epigone closed, 

 the other with the teeth of the epigone open, showing 

 the bursting sporange. Magn. 20 diams. 



Y 



