Abstract
1. A general veew of the meiotic processes in the PMC in vivo of Fritillaria was given. They were studied in the mass of the PMC covered with the tapetum tissue, the natural condition in the anther being kept as intact as possible.
2. Some phases in the meiosis in the PMC in vivo of Lilium longifolium were described in comparison with the above.
3. Considerations about the mechanism of the chromosome movement from the prometaphase to anaphase were given as follows:
a. The prometaphase begins after the third contraction of the chromosomes of the PMC. These chromosomes contract once, the surface membrane of the CPN crumples. The latter gradually absorbing water gives the opaque surface of the nucleus, which makes it difficult to observe the behaviours of the chromosomes inside the prometaphase.
b. The chromosomes gradually separate from each other in the reversing CPN and makes the chromosome plate.
c. With the chromosome plate as the equator the half spindles the atractoplast, are composed on both sides of the plate, the spindle pole appears on the surface of the CPN as the result of the electrostatic reduction due to the charged paired chromosomes in the CPN which is then in the dielectric condition in this phase, and this pole is the focus of the poles of each pair of the chromosomes. Consequently when the pole has just appeared, its sign of the charge is the same with that of the chromosomes, which keeps the chromosomes at the equator of the spindle, until the charge of the chromosomes reverses in the metaphase.
d. After that the sign of charge of the chromosomes reverses, then there results the force of traction between the chromosomes and the pole of the spindle.
4. The chromosome movement in the anaphase is conducted by:
a. the force of traction between the pole and the chromosomes,
b. the mutual repulsion between the separated n-chromosomes,
c. the passage in which the fibrous amphoteric molecules are arranged longitudinally in the force line due to the traction force differentiated, rejecting the short non-charged molecules in the spindle substance.
The cooperation of the above three plays an important role in the chromosome movement in the anaphase, in which the early movement of chromosomes is conducted mainly by their own repulsion, the next stage chiefly by the force of attraction, the passage giving convenience to the movement of the chromosomes.
5. The I prophase and the I prometaphase are very easily influenced by intra- as well as the inter-cellular condition and also by the condition given from outside. Therfore the whole length of the time of the meiotic processes may be determined by the condition first in the prophase and next by that in the prometaphase, the anaphase movement may be the least susceptible to outward influence among them.
