Atlas and epitome of human histology and microscopic anatomy / by Johannes Sobotta ; edited, with extensive additions, by G. Carl Huber.

  • Sobotta Johannes, 1869-1945.
Date:
1903
Catalogue details

Licence: In copyright

Credit: Atlas and epitome of human histology and microscopic anatomy / by Johannes Sobotta ; edited, with extensive additions, by G. Carl Huber. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    32/476 (page 26)
    star or (Hamster develops, eacli daughter star moving grad- ually nearer to its pole. At the same time a perceptible clongcition of the cell-body in the direction of the long axis of the spindle takes |)lace. The two daughter stars are connected by achromatic fibers, the so-(‘alled uniting fibers. These are probably the remains of the central s[)indle and in the center of their course often show thickenings called central spindle cor- jmscles, which mark the j)lace of the future division of the cell. Kven in the diaster stage the remains of the traction fibers still run from the chromosomes to the centrosomes, but seem to become shorter and shorter the farther the daughter stars are se])arated from each other. When the daughter stars are farther sej)arated, the dioi- sinn of the cell-body begins by a gradual ring-shaped con- stri(!tion of the cell near the middle (metaphase). When the constriction is nearly completed, a change of the daugh- ter stars into skeins begins. Just as the mother star was foruH'd from the skein, so now a skein is formed from each daughter star, and there is developed a mitotic figure known as the dispirem. At the same time the remains of the former spindle and the polar rays degenerate (ana- lihase). After the division of the cell-body is completed, a nuclear membrane is formed around each of the daughtei' skeins, and the new nuclei—daughter nuclei—are formed. The changes involved in this process, the alterations of the chromatin, etc., are collected under the term telophase. The division of the centrosome of each daughter cell may now take place (see page 22). When the indirect nuclear division is completed, each of the daughter cells has received half of the cell-body of the mother cell, half of the nucleus,—that is, half of each chromosome,—and half of the centrosome, or one of the two centrosomes now and then ])resent in the resting cell. Each daughter cell is therefore a counterpart of the mother cell.