- 459 
TABLE IV (in the dark). 
| Total Total Spirema | aoe 
Time. | number of | number of \and loose Monaster.| Diaster. ducten 
| nuclei. mitoses. | chrom, — 8 
| ys Sin eae 
6 a.m. 4702 446-0)... | 3,09 0 I) 1.40%, (10.4 .9/, 1020007 
12 a.m. | A004. | 4.98. 4) 3.49 0-40 oee 048 “1 Oa & 
| | 
6.30 p.m. | 4043 BOL zo!) 460 Oh ORDe el 5040 
| ‘ | 
As is evident, the number of karyokineses reaches its maximum 
between 8 a.m. and 11 a.m. (solar time), which agrees with the 
well-known fact that good cell-divisions in Hyacinth and Allium are 
found between 10 a.m. and 11 a.m. From 11 a.m. the number of 
cell-divisions decreases to 2.05 °/, at 3 p.m. 
I found the greatest number of karyokineses with the onion in 
the dark at 6 a.m., 4.46°/,. At 12 a.m. this had slightly decreased 
to 4.28°/,, and at 6.30 p.m. the decrease was still greater. At 6 a.m. 
and at 12 a.m. the maximum number of karyokineses in the dark 
exceeded the maximum number of cell-divisions found in the day- 
light, while the maximum number of karyokineses in the light sur- 
passed the minimum number of cell-divisions in the dark only by 
a slight degree; so that the conclusion seems justified: The number 
of karyokineses in the rootcells of Allium Cepa increases in the 
dark, which is stated by Karsten’) for Spirogyra and other plants. 
When we compare in the tables III and IV the number of 
spirema, loose chromosome stages with the number of monaster 
stages, then we see in the first table from 11 till 3 o’clock an in- 
crease of the number of spirema and loose chromosome stages and 
a decrease of the monaster stages. This would point to an increase 
in the number of cell-divisions and nevertheless the total number of 
mitoses has diminished. We see the same phenomenon on table LV 
from 6 a.m. to 12 a.m. 
By considering spirema, loose chromosomes and monaster as one 
stage (prophase) the number of nuclei in prophase, in table III at 
11 a.m. is 2.02°/, and at 3p.m. 1.74°/,, which points to a decrease. 
The same can be applied to table IV. At 6 a.m. 4.59°/, and at 
12 a.m. 3.98°/, and at 6.30 p.m. 2.31 °/, is in prophase, so there 
is a total decrease. In my opinion this fact is a confirmation of the 
general conception to consider spirema, loose chromosomes and 
monaster as one stage. *) 
EN Karsten. Zeitschr. f. Botanik 1918. 
2) PEKELHARING. Weefselleer, p. 67. 
