. Dansk botanisk arkiv. Plants; Plants -- Denmark. F. Borgesen: Rhodophyceæ of the Danish W. Indies. 311 come polysiphonous (cfr. Falkenberg, pi. 13, fig. 14). In the tetra- sporic plant, on the other hand, the upper end of the main stem in the trichoblast becomes polysiphonous and transformed into stichi- dia, while the lowest part remains monosiphonous (Fig. 317 a). The polysiphonous side-or- gans are developed quite inde- pendently of the trichoblasts. As pointed out by Falkenberg they are of later origin than the trichoblast, first appearing after the division of the seg- ments in the main
. Dansk botanisk arkiv. Plants; Plants -- Denmark. F. Borgesen: Rhodophyceæ of the Danish W. Indies. 311 come polysiphonous (cfr. Falkenberg, pi. 13, fig. 14). In the tetra- sporic plant, on the other hand, the upper end of the main stem in the trichoblast becomes polysiphonous and transformed into stichi- dia, while the lowest part remains monosiphonous (Fig. 317 a). The polysiphonous side-or- gans are developed quite inde- pendently of the trichoblasts. As pointed out by Falkenberg they are of later origin than the trichoblast, first appearing after the division of the seg- ments in the main filament and must be considered as ad- ventitious branches. Falken- berg found them rather regu- larly distributed, generally placed with ^4 divergency a single one upon each segment. In my plants the arrangement was not so regular, as segments without branches often occur- red. As indicated by Falken- berg the central axis of these reaches into the central cell in the main filament (Fig. 316); this, I think, largely supports the supposition that they really are of endogenous origin. The greatest part of these branches remains short, and spinelike;now and then a single one gets a continuous growi-h like the main filament and contributes to the ramification of the plant. The spinelike branchlets are of a rather soft consistence; they are always undivided and consist of up to ten segments with four pericentral cells, the segments getting smaller and smaller towards the top. In the uppermost segment only a single cell is present. From the basal pericentral cell of these branchlets hyphæ-like. Fig. 314. Wrightiella Tumanowiczii (Gatty) Schmitz. Part of a main axis with trichoblasts and spinelike branch- lets. From the basal cells of these hy- phæ are seen growing downwards for- ming the cortical layer. 'About 6U: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 ill
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