71 



only in the summits of the frond is it not so complete allowing 

 the red-brown tips of the assimilating filaments to protrude. 

 Also the cystocarps project above the calcareous layer and are 

 seen in the fruiting specimens as dark red dots (comp. fig. 71). 



The assimilating filaments have, as pointed out by J. AGARDH, 

 a corymbiform outline (Fig. 72). They reach a length of about 

 200 p. or somewhat more. 

 They are 4 5 times repea- 

 tedly forked. The uppermost 

 cells are pearshaped or broad 

 oval, about 10 12 // thick 

 (Fig. 73 b) ; lower down in 

 the filaments the cells grow 

 longer, at length becoming 

 subcylindric. The lowermost 

 cells are about 16^ thick. 



The central filaments 

 consist of subcvlindric cells 



t; 



somewhat tapering towards 



the ends (comp. figs. 72 and 



74 a) ; they are about 2040^ 



thick or more, and often reach 



a length up to 20 times their own diameter. They have very 



thick walls. Between these thicker filaments run thinner ones 



(lat. about 8/*), as the 

 transverse section of the 

 medullary tissue shows 

 (Fig. 74). 



These thin filaments 

 originate from the lower- 

 most cells in the assimila- 

 ting filaments (comp. fig. 

 75 a). They run between 

 or creep along the medul- 

 lary filaments ; and from 

 those near the surface 

 erect filaments arise (comp. 



fig. 73 a). They are somewhat branched and consist of oval cells ; 



they grow up between the assimilating filaments. As they have 



well developed chromatophores they may be considered as a kind 



of secondary assimilating filaments. 



The carpogonial branch is borne upon one of the cells in the 



Fig. 71. Liagora valida Harv. 

 Part of a plant. (About 3:1). 



Fig. 72. Liagora valida Harv. 



Assimilating filaments with carpogonial 



branches. (About 60 : 1). 



