. Dansk botanisk arkiv. Plants; Plants -- Denmark. F. Børgesen: List of species. 463 part of the filaments (Fig. 423 a). The rhizoids are unicellular, having in their basal end a flat roundish, coralhform disc. The rhizoids are given off mostly in the basal proximal ends of the cells near the cross walls (Fig. 423 a), but now and then, too, a rhizoid (mostly smaller) is issued in the upper (distal) end of the adjacent cell. The ramification is not very abundant; being mostly re- stricted to a few branches in the older parts of the thallus, the upper ends of the filaments often being undivided.
. Dansk botanisk arkiv. Plants; Plants -- Denmark. F. Børgesen: List of species. 463 part of the filaments (Fig. 423 a). The rhizoids are unicellular, having in their basal end a flat roundish, coralhform disc. The rhizoids are given off mostly in the basal proximal ends of the cells near the cross walls (Fig. 423 a), but now and then, too, a rhizoid (mostly smaller) is issued in the upper (distal) end of the adjacent cell. The ramification is not very abundant; being mostly re- stricted to a few branches in the older parts of the thallus, the upper ends of the filaments often being undivided. As pointed out by Asken AS Y a pecuharity is to be noted regarding the issue of the branches, these not being given off at the distal end of the cells, as is ordinarily the case in related forms, but near the basal wall of the cells (Fig. 423 a). The cells are nearly cylindrical or a little thicker at both ends; about 200 ju thick and 4—6 times as long. The wall is thick in the older parts of the thallus. Near the apex of the filaments the young cells become gradually shorter and a little swollen at their upper end. Round the upper end of the young cells is early formed a dense ring composed of several rows of hairs. These are di-trichoto- mously ramified and are soon shed, long before the cell has reached its normal size. The tetrasporan- gia (Fig. 423 b) are formed upon shorter or longer, pyriform to clavate, unicellular pe- dicels, one upon each of these. They form a dense ring at the upper ends of the cells, a little above that of the hairs or scars of these. AskenASY found Fig- 423. Criffithsia tenuis Ag a basal part of a plant, b, apex of filament with tetrasporangia. about ten only in each (a about 17:1 b, about 85:1).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Dansk botanisk forening. Kbenh
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