. Botany for high schools and colleges. Botany. 42 BOTANY. Win whole of IliR protop'asm of the mother-cell Is used. The former L& calls Free-OtU Fvrmation, the latter Formation of Cells- by Divmoit of the Mather- Cell, and includes also under the last a part of what has been described abr)ve under the head of Fission. It is doubtful, however, whether such a division is of much importance. (6) What has been called the Rejuvenescence of a cell may be mentioned here. The phenomena connected with it are as follows: The proto- plasm of a Cell contracts, ex- pels a portion of the water cont
. Botany for high schools and colleges. Botany. 42 BOTANY. Win whole of IliR protop'asm of the mother-cell Is used. The former L& calls Free-OtU Fvrmation, the latter Formation of Cells- by Divmoit of the Mather- Cell, and includes also under the last a part of what has been described abr)ve under the head of Fission. It is doubtful, however, whether such a division is of much importance. (6) What has been called the Rejuvenescence of a cell may be mentioned here. The phenomena connected with it are as follows: The proto- plasm of a Cell contracts, ex- pels a portion of the water contained in it, and escapes through a slit in its wall ; the naked mass becomes for a time a free-swimming zoos- pore, alter which it secretes a wall of cellulose, and begins to grow and form new cells by fission. Cases of this kind occur in (Edogonium, Stigeo- clonium, and many other aquatic Thallophytes. An interesting fact, but proba- bly of no great significance, is that the axis of growth of the new cell is perpendicular to that of the old one. While there can be no doubt that this process, as Sachs '-P«2TsrS«»«^/o.'^'ji. vertical section insists,* "must be regarded of ihe whole plant; ft, the layer morphologically as the for- iuwhi h the spore-forming sacK lie ,S. the tiesiie „„4. n » ^i of the futiKus envrliiping the hymenium at its matiou ot ii new cell, there edgeglnacuplikemanner;. at the baseof the can be little question that it tissue S Are threads aiise. which grow between . , , , , ^ , . the particles of earth. B, ii small portion of the is closely related to the forma- hymenium;/!A, layer of denselyin- tion of zoospores described terwoven filaments (hyphse); ffl to/, spore-form- ^ "v-owi,you ing sacs (am), with thin filaments (piraphyses) above (p. 40). The difier- belween them. AxW,Bx Sachs, gnce is that in the formation of ordinary zoospores the mother-cell breaks up into more than * See "Text-
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1888
