. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . rounding water(Johnson, 93; Pascher, 06 B). The smallerzoogonidia are biciliated in certain genera andthere is every probability that in some casesthey are facultative gametes. The gametes are always biciliated and thezygote rests for a short time before zoogonidia as a rule only swarm forabout ten minutes, and they germinate at onceon coming to rest. The cilia are lost and thecell rapidly increases in length,one pole generall
. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . rounding water(Johnson, 93; Pascher, 06 B). The smallerzoogonidia are biciliated in certain genera andthere is every probability that in some casesthey are facultative gametes. The gametes are always biciliated and thezygote rests for a short time before zoogonidia as a rule only swarm forabout ten minutes, and they germinate at onceon coming to rest. The cilia are lost and thecell rapidly increases in length,one pole generally elongating to form a hair-like multicellular outgrowth. The young plantvery soon begins to branch and in some genera a basal recumbent portionis first developed, whereas in others the attachment is by a specially modifiedbasal cell, as in Thamnioch&te aculeata (vide G. S. W., 04) and in some formsof Stigeoclonium (Fritsch, 03)1. A variable development of rhizoids occurs 1 Fritsch records the occurrence of a brownish-red salt of iron deposited about theattachment-surface of the basal cell in St. varlabile, which probably serves the purpose of. B Fig. 190. Draparnaldia platy-zonata Hazen. A, small portionof plant, x 70. B, single cell ofmain filament showing the re-ticulated chloroplast, x 180.(From a specimen collected inBritish Columbia by Mr F. ) Chaetophorese 297 in the young plants of the larger genera. The zoogonidia of Stigeocloniumand Chietopliora often develop in masses, and in many instances the adultthallus is really a colony of plants which have grown intermingled.
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