. Annals of the South African Museum. Annale van die Suid-Afrikaanse Museum. Natural history. The Freshwater Algae of Africa. 513 of the colonies were quite free. The spherical cells are connected together by processes which are broader and shorter than the warts which occur on the free surface of the cells (Fig. 9, a c). These warts were emarginate-truncate, as in the specimens recorded by Messrs. \Y. & G. S. West; but they were certainly fewer (the largest number observed on a single cell being 16) and further apart (>/'. Fig. 9). In many cases they appear to widen out slightly from t
. Annals of the South African Museum. Annale van die Suid-Afrikaanse Museum. Natural history. The Freshwater Algae of Africa. 513 of the colonies were quite free. The spherical cells are connected together by processes which are broader and shorter than the warts which occur on the free surface of the cells (Fig. 9, a c). These warts were emarginate-truncate, as in the specimens recorded by Messrs. \Y. & G. S. West; but they were certainly fewer (the largest number observed on a single cell being 16) and further apart (>/'. Fig. 9). In many cases they appear to widen out slightly from the base. The length of these warts varies considerably in different specimens, the dimensions given above being the maximum Fig. 9.—Coelastrum morus, \\ . and G. S. West, forma capensis, nov. form. a, c, d. Various forms of the colonies ; in d the colony is still enclosed within the membrane of the mother-cell. b. Single cell, showing warts and the broad process for attachment to neighbouring cells ; the con- tents arc undergoing division. bl. Cell in optical section, showing the thick membrane. All figures x 750. The cells were grouped in very various ways, which is probably a result of the mode of life. Apart from typical Coelastrum-gvou^iiigs (Fig. 9, d), irregular colonies were frequent (Fig. 9, c). Not un- commonly the cells were found in two superposed groups of four (Fig. 9, a), the four cells of each tier being separated in the middle by a quadrilateral space, so that a surface-view of such a colonv appeared much like a Crucigenia. The details of the cell-contents were not very clear, but the cells appeared to have a single pyrenoid. The membrane is strongly thickened (Fig. 9, &'). Genus DICTYOSPHAERIUM 1. Dictyosphaerium ehrenbergianum, Naegeli, Gatt. einzell. Algeu., 1849, p. 74, Tab. II, E. Sample 14 (very rare).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - colorat
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Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
