Ill 



J/A RCHANTIE.'E 



The further growth of the spores and clatcrs was studied in 

 Fimbriaria Californica. The spores remain together in tetrads, 

 until nearly ripe. In sections parallel to the surface of the 

 younger spores (Fig. 24, C) the outer surface of the exospore 

 is covered with very irregular sinuous thickenings, at first 

 projecting but little above the surface, but afterward becoming 

 in this species extraordinarily developed. In sections of the 

 ripe spore (Fig. 24, D) three distinct layers are evident, the 

 cellulose endospore, the thick exospore, and this outer thickened 



Fig. 24. — Fimbriaria Californica (Hampe). A, Young elater x6oo; B, a fully -grown elater, 

 X 300 ; C, surface view of the wall of a young spore, showing the developing episporic ridges, 

 x6oo; D, section of the wall of a ripe spore, X300. ; 



mass of projecting ridges which has every appearance of being 

 deposited from without, and must therefore be characterised as 

 epispore (perinium) ; Leitgeb ^ distinctly states that thickenings 

 of this character do not occur in the Marchantieae, but that the 

 thickenings are always of the character of those in Riccia. 



The elaters are at first elongated thin-walled cells with a 

 distinct although small nucleus, and nearly uniformly granular 

 cytoplasm. As they grow the cytoplasm loses this uniform 

 appearance, and a careful examination, especially of sections, 

 shows that the granular part of the cytoplasm begins to form 



^ Leitgeb (7), vol. vi. p. 45. 



