Archive image from page 11 of A cytological study of haploid. A cytological study of haploid Crepis capillaris plants cytologicalstudy64holl Year: 1930 116 University of California Publications in Agricultural Sciences [Vol. 6 ing chromosomes as four, the total of twelve suggests two successive divisions of three, or a single division of six univalents, the cause of either of which is obscure. A later stage—very early telophase— resulting from such a complex, is shown in figure lb. Twelve chro mosomes in groups of various numbers are to be seen and nucleoli and nuclear membranes are being di
Archive image from page 11 of A cytological study of haploid. A cytological study of haploid Crepis capillaris plants cytologicalstudy64holl Year: 1930 116 University of California Publications in Agricultural Sciences [Vol. 6 ing chromosomes as four, the total of twelve suggests two successive divisions of three, or a single division of six univalents, the cause of either of which is obscure. A later stage—very early telophase— resulting from such a complex, is shown in figure lb. Twelve chro mosomes in groups of various numbers are to be seen and nucleoli and nuclear membranes are being differentiated. Other cells with twelve chromosomes in two or three groups at telophase were also observed. One instance of two metaphase plates in a single PMC, each con- taining three bivalents, was observed (fig. 8). No explanation of this unusual occurrence is ventured. The number and constitution of telophase nuclei are readily studied at this stage, for contrary to the normal behavior in this Fig. 8. Haploid Crepis capillaris. A cell containing two 1M plates each consisting of three bivalents. genus, in most cases the chromosomes are clearly outlined and often can be distinguished from each other by their relative sizes in the telophase nuclei. Occasionally, however, a group of telophases is ob- served in which the chromosome outlines are not clear and the reform- ing nuclei resemble masses of chromatin. Telophase usually begins with the appearance of a clear area in the cytoplasm surrounding a clearly outlined chromosome or group of such chromosomes. An instance of an interesting and rare stage, the appearance of a faint nucleolus near each group of chromosomes before the appearance of the nuclear membrane, was observed, and is shown in figure 9a. Occasionally the nuclear membrane is formed around a chromosome or group of chromosomes without including a nucleolus. The telo- phase chromosomes elongate and commonly total six in number (fig. 9, b-f). Chromosomes whose
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