150 MR A. ANSTRUTHER LAWSON ON 
25 there is no trace whatever of such a disturbance in the cytoplasm. There is no 
evidence of any sort to support the view that a movement and coalescence of the 
cones really occurs, except the fact that we eventually have a bipolar figure in place of 
one which was previously multipolar. Throughout all of these stages it will be seen 
that the nuclear membrane, which in reality constitutes the bases of the cones, is con- 
stantly moving inward as it closes in about the chromosomes, and as the nuclear 
vacuole becomes smaller and smaller the area of the membrane becomes less and less. 
With these changes there necessarily follows a corresponding shifting in the lines of 
tension ; so that during the entire prophase there is a constant changing in the dis- 
tribution of the kinoplasm. ‘The ultimate bipolarity of the spindle is therefore not 
brought about by the approachment and coalescence of the cones in two groups, but 
by the shifting of the osmotic surfaces which form the bases of the lines of tension 
represented in the threads of kinoplasm. 
In fig. 22 we have a condition where the karyolymph has been reduced by diffusion 
to such an extent that the chromosomes have become crowded together around the 
nucleolus. The nuclear membrane is now in close touch with several of the chromo- 
somes. In the lower part of the figure one of the chromosomes seems to be already 
partly enfolded by the membrane. That this enveloping process continues until the 
membrane becomes closely applied to the entire surface of each chromosome is in my 
opinion beyond much doubt. To make an actual demonstration of the plasmatic 
membrane during its close application to the surface of the chromosomes is obviously 
out of the question. We are, therefore, obliged to accept less convincing evidence. 
In fig. 22, however, we have undoubtedly the beginning of such a process. If we 
compare figs. 22 and 23, and examine them in the light of the evidence obtained 
in similar stages in the case of Disporum, there is really only one rational conclusion to 
come to. It is, namely, that each chromosome has not only been completely and closely 
enveloped by a membrane, but each of these bodies, as a result of that enveloping 
process, has been furnished with a system of kinoplasmic fibrils. With the establish- 
ment of as many osmotic systems as there are chromosomes—systems which are to a 
great extent quite independent of one another-—there will naturally follow a new and 
rapid readjustment of the lines of tension expressed in the kinoplasm. Such a 
readjustment is probably taking place in the stage represented in fig. 24. 
As stated above, the chromosomes in Gladiolus are very long, being many times 
longer than broad. It would therefore follow that as the nuclear membrane became 
closely applied to the chromosomes, the broad sides of these bodies, offering the greater 
osmotic surfaces, would naturally be thus furnished with many more kinoplasmic threads 
than the short end surfaces. ‘This condition may be seen quite clearly in figs. 23 and 
24. And so with the final readjustment, the main lines of kinoplasm would find 
themselves exerting a tension on opposite sides and at right angles to the long axis 
of each chromosome, and these latter bodies would thus be suspended at the equator, 
as shown in fig. 25. 
