. The origin of a land flora, a theory based upon the facts of alternation. Plant morphology. Fig. 40-. Germination o$ Clostcriitm, after Klebahn. I. Zygote before unclear fusion. 2. First mitosis. 3. Bi-nuclear stage. 4. Second mitosis 5.' Bi-cellular stage with large and small nuclei. 6. Formation of the two germs. (From Oltmanns.) (Fig. 41), the protoplasts of the two cells come into close relation, but the nuclei remain distinct (Fig. 41. 2), and undergo each a division into two, and again into four (Fig. 41. 3, 4): of these, two in each cell are soon reduced in size, while the others are
. The origin of a land flora, a theory based upon the facts of alternation. Plant morphology. Fig. 40-. Germination o$ Clostcriitm, after Klebahn. I. Zygote before unclear fusion. 2. First mitosis. 3. Bi-nuclear stage. 4. Second mitosis 5.' Bi-cellular stage with large and small nuclei. 6. Formation of the two germs. (From Oltmanns.) (Fig. 41), the protoplasts of the two cells come into close relation, but the nuclei remain distinct (Fig. 41. 2), and undergo each a division into two, and again into four (Fig. 41. 3, 4): of these, two in each cell are soon reduced in size, while the others are distinguished by their larger size (Fig. 41. 4). Then comes an abstriction of each of the original protoplasts into halves, and each half contains two nuclei, one large and one small (Fig. 41. 5): these halves coalesce in pairs, and each fusion-pair finally develops into an auxospore (Fig. 41. 6, 7): the two larger nuclei of each pair meanwhile fuse, while the smaller nuclei become disorganised (Fig. 41. 8). In these cases there is conjugation, and a tetrad-division of nuclei accompanies it. There is no evidence as yet of chromosome-number, 1 Pringsh. Jahrb., vol. 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 Bower, F. O. (Frederick Orpen), 1855-1948. London, Macmillan and Co. , Ltd.
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