. Botany for high schools and colleges. Botany. (EDOOONIE^. 247 329.—The asexual reproduction of CEdogouiese is as curi- ous as the growth of its cells, just described. During the early and active growth of the plants the protoplasmic contents of certain cells in a filament become detached from their walls, and upon the splitting of the latter the now rounded protoplasm escapes as a large zoospore (Fig. 166, A and B); it is oval in shape, and provid- ed with a crown of cilia about its smaller hyaline end, by means of which it swims rapidly hither and thither in the water (Pig. 166, C). After a
. Botany for high schools and colleges. Botany. (EDOOONIE^. 247 329.—The asexual reproduction of CEdogouiese is as curi- ous as the growth of its cells, just described. During the early and active growth of the plants the protoplasmic contents of certain cells in a filament become detached from their walls, and upon the splitting of the latter the now rounded protoplasm escapes as a large zoospore (Fig. 166, A and B); it is oval in shape, and provid- ed with a crown of cilia about its smaller hyaline end, by means of which it swims rapidly hither and thither in the water (Pig. 166, C). After a time it comes to rest, clothes itself with a cell-wall, and sends out from its smaller end root- like prolongations (Fig. 166, D), which attach it to some object; it now elongates, and at length forms partitions, taking on eventually the form of the adult filament. It sometimes happens that before the new plant resulting from the growth of a zoospore has formed its first partition, the protoplasm sep- arates from its wall and again aban- dons it, to be for a time a zoospore (Fig. 166, E). This method of formation of zoospores is what Braun called Eejuvenescence. (See p. 43.) 330.—The sexual reproduction of the plants of this class is in. Fig. 166. — Asexual reproduc- tion of (Edogoniuni, A, fracture of a filament and escape of the protoplasm of the broken cell; the protoplasm, in the whole cell below is seen to be somewhat withdrawn from the cell-wall, preparatory lo escaping. S, es- cape of protoplasm and formation of a zoospore; the hyaline por- tion of the latter ia seen to be lat- eral. O, a ciliated and swimming zoospore, th« hyaline portion now 1 1 1 IT J 1. J. terminal. D. zoospore at rest, many respects closely allied to that and sendlne out root-like pro- of SpJKBToplea. The female organs ^^rT?o";o'f are in all cases developed in essen- e"8cIp?Sr'x"^^-Afrr'p?!Sg? tially the same way, but the male *^^™- organs present a
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1885
