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



355 



struction of the stem, but as this is rather brief. I shall give a fur- 

 ther description together with some figures. 



l^pon a transverse section of the main stem in the neighbourhood 

 of the place where the pair of branches issue we find an arrangement 

 like that shown in Fig. 350 6. The central cell is here very large, its 

 diameter reaching a length of about 180 \x. It is surrounded by a cir- 

 cular open space filled with sap, round which again follows the rather 

 thick, parenchymatous, peripheral tissue. On both sides of the central 

 cell, but not exactly op- 

 posite, two filaments 

 issue. One of these fila- 

 ments is thicker and 

 more vigorous than the 

 other and both extend 

 themselves in the bran- 

 ches given off here the 

 more vigorous in the 

 thickest, the other in the 

 thinnest of the two bran- 

 ches. From the first cell 

 of these ramifications, 

 the one nearest to the 

 central cell, thin hyphæ- 

 like filaments issue in 

 all directions, the cells 

 in this way becoming 

 stellately ramified. These 

 thin filaments run up and down in the space within the interior 

 wall of the peripheral tissue ; they are rather irregularly, often sub- 

 dichotomically, ramified. The peripheral tissue itself consists of 

 5 — 6 layers of cells of roundish shape, largest in the interior, de- 

 creasing gradually towards the periphery. 



A longitudinal section (Fig. 350 a) shows that the central axis 

 consists of very long cells about 1500 \x long, being in the upper 

 part cylindrical (about 45 n thick) and in their lowest part much 

 swollen, nearly globular. It is from this globular part that the 

 branches issue. 



Of this plant only female ones were gathered. The procarps oc- 

 curred at the tip of short clavate branchlets (Fig. 351^) growing 



23* 



Fig. 351. Asparagopsis taxiformis (Delile) 



Collins et Hervey. 



.4, part of a branch with procarp. (25:1); 



B, cystocarp (about 8:1). 



