326 



softer consistence. The ramification of the branches is scarcer, the 

 branches are slender with thinner and longer cells ; the unbranched 

 summit of the first branch in the branch-system is especially much 

 elongated. In the basal part of the monosiphonous ends of these 

 branches the cells are about 40 (a thick and their length about 70 ja. 

 Towards the top the cells become somewhat longer (about 120 u), 



tapering at the same 

 time evenly to the 

 summit where the 

 breadth is about 25 

 u. The uppermost 

 end of the filaments 

 is often a little swol- 

 len or it becomes 



rhizoid-like (Fig. 

 328 b). 



In this form the 

 polysiphonous axi& 

 has always 4 peri- 

 central cells and ne- 

 ver more (Fig. 328 c). 

 \Yhile all the gather- 

 ings of the squarrose 

 form were sterile,, 

 this one had stichi- 

 dia with ripe tetra- 

 spores (Fig. 327). 

 The stichidia (Fig. 

 328 a) are placed at 

 the ends of one of the ramifications of the second branch. They 

 are acute, subcylindrical of shape with broadly rounded base. In 

 the cylindrical part they are about 110 |u thick. They have a 

 longer or shorter, monosiphonous stalk composed of a variable num- 

 lirr of cells up to ten. 



My description above proves that the two forms are very different, 

 and FALKENBERG, too, points out that perhaps we have to do with 

 two different species. As they agree in so many respects I 

 I IT for to consider them only as varieties of the same plant. The first 

 one, the squarrose form, according to FALKENBERG being like the 



l-'i.^. o27. HeterosiphoniaWurdemanni (Bail.) Falkb. 

 y;ir. I ax. a n. var. t'pper part of the thalius with 



vomit; stichidia. 



'(About 35: 1). 



