. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . It is probable that some of the described speciesof Gloeocystis, such as Ol. vesiculosa Nag., are merely the palmella-states of species ofChlamydomoii as. A vegetative resting-state has been found to occur in certain species(Chi. alpina, Chi. gigantea, Chi. nivalis, etc.) and Wille (03) has suggestedthat several of the described species of Trochiscia (= Acanthococcus) aremerely the resting-cells (akinetes) of Chlamydomonads. There is, however
. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . It is probable that some of the described speciesof Gloeocystis, such as Ol. vesiculosa Nag., are merely the palmella-states of species ofChlamydomoii as. A vegetative resting-state has been found to occur in certain species(Chi. alpina, Chi. gigantea, Chi. nivalis, etc.) and Wille (03) has suggestedthat several of the described species of Trochiscia (= Acanthococcus) aremerely the resting-cells (akinetes) of Chlamydomonads. There is, however,as yet no definite proof of this. Planogametes are known to occur in a number of the species; they arein all cases similar to the vegetative cells (= zoogonidia), but smaller andare produced up to 64 in the mother-cell. They are generally naked, but insome species they may be clothed with a cell-wall (Chi. media Klebs ; fig. 92 0and H). In most cases the gametes are isogamous, but in some speciesheterogametes (anisogametes) occur, and in Chi. monadina Stein the conjuga-tion of the gametes is a case of true oogamy, the contents of the megagamete. J Fig. 101. A—F, Brachiomonas sitbmarina Bohlin ; A and B, side views of vegetative individuals(zoogonidia); C, anterior view; D, formation of four zoogonidia (daughter-cells) within oldinother-cell-wall; E, gamete; F, zygote. G and H, Phacotus lenticularis Stein, two viewsshowing compression of cell. I, Lobomonas stellata Chodat; J, Lobomonas Francei , nucleus ; py, pyrenoid; r, vacuole. A—F, x 1000; G and H, x 800; I, very highlymagnified (after Chodat) ; J, x 1000 (after Dangeard). acting as an egg-cell (fig. 100 1—3}. The zygote often exhibits distinctspecific characters, being adorned with short spines, warts, etc., or variouslysculptured. This genus {.Chlamydomonas] holds a unique position among the Green Algae, andindeed among the whole of the Green Plants. It may lie regarded as the phylogenetic Chlamydomonade
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