. Text-book of normal histology: including an account of the development of the tissues and of the organs. r Vs appearas radiating fibrils, and constitute the (4) Mother-star, or aster : the apparent dif-ferences, therefore, between the wreath and theaster depend upon the point of view, and notupon variations in the arrangement of the completion of these preparatory changesmarks the termination of the prophases ; the suc-ceeding metaphase is initiated by an importantchange leading to the reapportionment of thechromatin. (5) Each of the loops, or chromosomes, un-dergoes longitudinal
. Text-book of normal histology: including an account of the development of the tissues and of the organs. r Vs appearas radiating fibrils, and constitute the (4) Mother-star, or aster : the apparent dif-ferences, therefore, between the wreath and theaster depend upon the point of view, and notupon variations in the arrangement of the completion of these preparatory changesmarks the termination of the prophases ; the suc-ceeding metaphase is initiated by an importantchange leading to the reapportionment of thechromatin. (5) Each of the loops, or chromosomes, un-dergoes longitudinal cleavage, splitting upinto double the number of segments : these arenow entirely rearranged during the anaphases,the first step being (6) A rapid separation into two groups, pass-ing towards the poles of the future new nuclei,as indicated by the foci of the nuclear spindle. Around these pointsas centres, a delicate radial marking—the polar striation— halves of the longitudinally cleft fibrils are so disposed that oneof each pair of sister-segments passes along the guiding lines of the 2. GP Rearrangement andcleavage of V-segments:A, from the side; £.from the polar field, P:GP, anti-pole. (AfterRcibl-Schiefferdecker.) i8 NORMAL HISTOLOGY. achromatin sj:)indle to each of the groups, thus insuring an accurateand equal cHvision of the original chromatin between the new chromatic segments, becoming further aggregated about theequator of the nuclear spindle in their migration, form a compressedmass, known as the (7) Equatorial plate.* As the newly-grouped fibrils pass out-ward towards their respective poles, the free ends of the recedingsegments become united by delicate threads of achromatin—theconnecting filaments—which stretch between the correspondinglimbs of the separating segments. With the completion of migra-tion the cardinal features of the division of the nucleus have beenestablished, since the anaphases are but repetitions, in inverse order,o
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