UNIVERSITATIS LATVIENSIS - DSpace

Studies in the change of the volume of cells
during division.
By
Karlis Abele.
In order to observe the change in the volume of cells during
the division of cells and nuclei the cells of the roots of Allium
cepa have been measured. The roots fixed in Carnoy's solution
and embedded in paraffin of m. p. 52° C. are cut at 15ja.
Such a
thickness allows us to measure the nuclei without changing their
size and gives comparatively few nuclei cut or destroyed: in
fact they generally prove to be intact.
For clear up the questions about the period
of the most
intensive growth of the cell and about the proportion between
the volume of the cell and that of the nucleus during the growth
of the cell, the cells in the length sections are
measured. For
that purpose the cells are drawn with the aid of an Abbe camera
lucida, the obtained copies measured and the results calculated
2
in mm The .
nuclei are measured by the same method.
The size of the sections of measured cells with nucleus in
2
the early prophase of the division varies from 910 mm
2GO mm 2
,
the
average
result beeing 496,8 mm
2
. The size of the
2
sections of the nucleus varies from 255 mm
average result beeing 148,9
mm 2
. The
proportions
2
to 100 mm
,
measured sections of cell and nucleus varies from 5,5:
to
the
betveen the
1 to 2: 1.
The average result is 3,34:1. In the same way are measured
the cells close by the left and the right side (length direction)
with the nuclei in the resting stage. The plain
of cells varies between 620 mm 2 and 190 mm 2
result is 313,4 mm2
.
of the section
,
the average
The results obtained from the measurement
2 2
of nuclei
vary
between 155 mm and55 mm the
average beeing
,
88,7 mm2
. The
proportion between the measured sections of
cell and nucleus varies from 6,7:1 to 2,4:1. The average
result is 3,6: 1.
Acta Horli Bot. Unlvera. Latv. 11.
4