. Dansk botanisk arkiv. Plants; Plants -- Denmark. F. Børgesen: List of species. 425. of the specimens the original basal rhizoids were present, the plants being fixed by means of them to the rocks. Most probably the end-rhizoid had been cut off during the gathering in the spe- cimens in which it was absent. The basal rhizoid (comp. Fig. 406 and 407) is below broad- ened out to a small disc with irregular coralliform outline, and the base on the whole becomes gradually strengthened by means of throughgrowing of the lowermost cells in the filament down into the basal cell in a way similar to th
. Dansk botanisk arkiv. Plants; Plants -- Denmark. F. Børgesen: List of species. 425. of the specimens the original basal rhizoids were present, the plants being fixed by means of them to the rocks. Most probably the end-rhizoid had been cut off during the gathering in the spe- cimens in which it was absent. The basal rhizoid (comp. Fig. 406 and 407) is below broad- ened out to a small disc with irregular coralliform outline, and the base on the whole becomes gradually strengthened by means of throughgrowing of the lowermost cells in the filament down into the basal cell in a way similar to that known so well in Chætomorpha. This throughgrowing can take place in three to four of the basal cells, the lowermost cell in this way becoming rather long. As already mentioned the original basal rhizoid in Rhizoclonium is very rarely found. Regarding Rhizoclonium Kerneri Stockm. Wille in "Studien über Chloro- phyceen", VII, p. 41 writes, as follows, concerning the basal rhizoid: »Beim Kei- men der Zoosporen bildet sich ein basales Endrhizoid (Taf. IV, Fig. 166—68); aber da sich die Fäden durch intercalare Teilungen und zufällige Zerreissungen sehr stark vermehren, so findet man Fäden mit Endrhizoid sehr selten. Inwiefern die Fäden ursprüng- lich festsitzen, kann ich nicht mit Sicherheit ausmachen, viel- leicht darf die eigentümliche starke Verdickung an dem abgebil- deten Rhizoid (Taf. IV, Fig. 168) als eine abnorme Entwickelung gedeutet werden, indem sie keine Gelegenheit gehabt hatte sich zu befestigen, da dieses Exemplar nur loose zwichen den übrigen Fäden hing«. Regarding the presence of basal rhizoids in my specimens no doubt is possible. They were vigorously developed and present in all the specimens. As the plants have no other rhi- zoids to fix themselves with they would immediately have been washed away by the waves, if they had not been fixed by the basal rhizoids. The filaments increase by means of intercalary divisions of the cells, these
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