. A handbook of cryptogamic botany. Cryptogams. 235 duction consisting in the impregnation of a passive oosphere by motile antherozoids attains its highest development among Alg». The antherozoids retain their motility and vitality for from one to three days. The oospheres will show signs of a rudimentary germination even when unfertilised, but in that case the germ soon perishes. Thuret succeeded in obtaining a hybrid Fucus by impregnating the oospheres of F. vesicu- losus (L.) by the antherozoids of F. serratus (L.). A short time after impregnation the oosperm invests itself with a
. A handbook of cryptogamic botany. Cryptogams. 235 duction consisting in the impregnation of a passive oosphere by motile antherozoids attains its highest development among Alg». The antherozoids retain their motility and vitality for from one to three days. The oospheres will show signs of a rudimentary germination even when unfertilised, but in that case the germ soon perishes. Thuret succeeded in obtaining a hybrid Fucus by impregnating the oospheres of F. vesicu- losus (L.) by the antherozoids of F. serratus (L.). A short time after impregnation the oosperm invests itself with a cell-wall, fixes itself to some other body, and begins to germinate with- out any intervening period of rest. The first transverse division of the young germinating filament is followed by others in various direc- tions, so that a solid mass of pseudo- parenchyme is at length formed, fixed to the bottom by a root-like rhizoid. The Fucaceae constitute a small and well - marked family of seaweeds, united by some sys- tematists with the PhaeosporeEe, or at least with the Lami- nariaces, to make up the Fucoideffi of Agardh, or the Melanospermeae of Harvey. They are, however, well dis- tinguished by their mode of reproduc- tion. The family is represented in Britain by the genera Halidrys (Grev.), Cystosira (Ag.), Pycnophycus (Ktz.), Fucus (L.), Ascophylla (Stackh.), and Himanthalia (Lyng.), and includes also the exotic genera Sargassum (Ag.), Pelvetia (Dene.), Durvillsea(Bory), Splachnidium(Grev.), and a few others. Although the number of native British species described by Harvey is only thirteen, some of these occur in such vast quantities that the Fucaceae. Fig. 211.—The gulfweed, Sargassuvi lacciferum Ag. (natural size).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Bennett, Alfred W. (Alfred William),
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