216 MARY T. HARMAN 
condition, for I find it with all the different fixations and stains. 
There is no indication whatever of poor fixation in those slides 
from which I have taken my drawings.? 
Judging from the comparative size of the nuclei, the first divi- 
sion is an equal one. This is what would be expected if the divi- 
sion is mitotic. Soon after the first division there is a difference 
in the rate of nuclear division. I cannot say at just which divi- 
sion this difference in rate occurs. All the figures in plate 7 show 
nuclei of different sizes. I have never found two nuclei differ- 
ing appreciably in size in which I could find evidence with any 
degree of certainty that they came from the same mother nucleus. 
For this reason I account for the difference in size of the nuclei 
by a difference in the rate of nuclear division. 
b. Length and position of the spindle. As I have said before, 
the segmentation spindle may be long or short and may lie in 
almost any position with reference to the periphery of the cell. 
It may lie near the center of the cell with the cytoplasm almost 
equally distributed around it, as in figures A and B, plate 4, or 
near the periphery, as in figures E and F of the same plate. In 
these cases the spindle is comparatively short. Figures C and D, 
plate 4, show the position of the spindle intermediate between 
those shown in figures A and F of this plate, but of the same rela- 
tive length. In figure H of the same plate the spindle is very 
long, extending from one side of the cell to the other. Figures 
I and J, plate 4, show cells in very late anaphase of first segmen- 
tation. The spindle fibers are not visible, but.the centrosome 
and the masses of chromatin are very plainly visible. There is 
no doubt that in these cases the spindle was long. Figure G of 
the same plate shows a cell which has a spindle comparatively 
longer than those shown in figures A to F inclusive, and shorter 
than those shown in figures H to J inclusive, of this plate. All 
these are examples of the first segmentation spindles. 
The same variation of the relative length and position of the 
spindle is found in later segmentations. However, here the length 
may depend somewhat upon the size of the nucleus, which is, 
* Dr. Richards has seen some of my slides and says there is no question but 
that the fixation is good. However, he did not examine them with reference to 
the question of a syncytium. 
