F. Børgesen: Rhodophyceæ of the Danish W. Indies. 



75 



occur which reach more than 100 ii in diameter ; besides these 

 cells there are many of a much more irregular form. 



The assimilating filaments (Fig. 75 a) 

 consist at their base of nearly cylindric cells 

 about 40 /i thick and 2 — 3 times as long as 

 broad. The filaments branch several times 

 (4 — 5 or more) the cells at the same time 

 becoming gradually thinner, the thinnest 

 being found somewhat over the middle of 

 each cluster of filaments ; then they grow 

 thicker again until near the top where they 

 suddenly narrow conically. In the cluster 

 of filaments represented in fig. 77 a the cell at the base is 40/i 

 thick, the thinnest cells in the middle of the cluster are 11// 

 and the thickest near the top 25/«. 



Fig. 78. Liagora pin- 

 na?a Harv. Transverse 

 section of medullary 

 layer. (About 60: 1). 



Fig. 79. Liagora pinnata Harv. a, carpogonial branch, 



b, c, d, development of the cystocarp, (a and b, about 



160: 1, c and (/ 150: 1). 



From the basal cell, and sometimes also from other of the 

 lower cells in the cluster of assimilating filaments, rhizoidal fila- 

 ments grow out along the central large filaments (77 a). These 

 rhizoidal filaments consist of long more or less cylindrical or some- 

 what inflated cells ; from these erect filaments grow up the 

 cells of which are shorter but often rather thick, oval or rather 

 irregularly inflated, the filaments in this way getting a somewhat 

 moniliform appearance ; these filaments become intermingled be- 

 tween the assimilating filaments of the periphery. 



Somew^hat below the middle in the cluster of the assimilating 

 filaments we find the carpogonial branch (Fig. 77 a). This is 

 placed laterally upon one of the cylindrical cells found here, and 



