. The Botanical magazine. Plants; Plants -- Japan. Sept, 1921.] YASUI:— ON THE BEHAVIOR OF CHROMOSOMES 159 form a small pollen grain by itself, so that some pollen mother cells contain some extra pollen grain or grains. pollen mother cells, "with young pollen grains formed in it. a? four pollen grains formed ? b? a mother cell containing four pollen grains, one at center with an isolated chromosome besides a normal nucleus, one to the left and one below, containing no nuclei, under way of degeneration ? c, two grains contain each an extra dwarf nucleus ? d, a mother cell
. The Botanical magazine. Plants; Plants -- Japan. Sept, 1921.] YASUI:— ON THE BEHAVIOR OF CHROMOSOMES 159 form a small pollen grain by itself, so that some pollen mother cells contain some extra pollen grain or grains. pollen mother cells, "with young pollen grains formed in it. a? four pollen grains formed ? b? a mother cell containing four pollen grains, one at center with an isolated chromosome besides a normal nucleus, one to the left and one below, containing no nuclei, under way of degeneration ? c, two grains contain each an extra dwarf nucleus ? d, a mother cell containing four normal sized pollen grains and a dwarf pollen grain ? e? a mother cell containing one abnormally large pollen grain (diploid), two ordinary pollen grains and a dwarf pollen grain ? f? a mother cell having two unusually large (diploid) pollen grains. The division of thelar?e nucleus, resulting from the fusion of the two daughter nuclei, formed by the first division, very much resembles an ordinary somatic division ? and it results in the forma- tion of two large daughter nuclei ( Fig. 23), each of whicn has naturally an excessive number of chromosomes for a haplom nucleus. Thus the latere pollen grains, only two in ntimber contained in a mother cell, may be produced. (,f). In some specimen, two daughter nticiei of the first division, having no partition wall between, are situated very near to each other ? then the two spindles of the second division disturb each other, so that there arise great irregularities. Likewise the two groups of telophasic chromosomes derived from two different nuclei sometimes. 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 Tokyo Shokubutsu Gakkai; Nihon Shokubutsu Gakkai. Tokyo : Tokyo Botanical Society
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectplants, bookyear1887
