1 98 Lloyd Williams . — Studies in the Dictyotaceae. 
late period of the anaphase stage, in the division figures of parthenogenetic 
nuclei the membrane is invariably absent. The disappearance must be 
very rapid., for in all the hundreds of cases examined I have never met 
with any where the dissolution was partial. Coincidently with the 
disappearance of the membrane the nuclear space, now sharply delimited 
by the crowded chloroplasts and coarser reticulation, is seen to be 
occupied with very fine meshed or finely fibrillar ‘ kinoplasm,’ in which 
long fibres can be distinguished. No two figures are alike in the arrange- 
ment of the threads. Some of the most regular are shown in Figs. 33-36. 
In many the longer threads cross each other in inextricable confusion, 
so that no two can be seen to converge. In such cases it almost seems 
an abuse of language to call them spindle-fibres. 
A point in which these figures present a sharp contrast to the 
artificially produced multipolar figures of animal eggs is the total absence 
of both centrosomes and radiations. The figure is entirely confined 
to the nuclear space, and no cytasters or any other radiate structures 
are seen outside. This is the more remarkable as centrospheres are such 
prominent features in normal mitoses. 
The subsequent history of the dividing nucleus is rather peculiar. 
In the dense ‘ kinoplasmic ’ mass a number of approximately spherical 
lighter areas appear, and in each area one or several curved chromosomes. 
Very soon after differentiation each area is delimited by a membrane, 
and the interior of the dense felt of kinoplasm is occupied by a cluster 
of nuclei, some large and some small, the size generally depending upon 
the number of the contained chromosomes (Figs. 37, 39). I have been 
unable as yet to decide whether as a preparation for this stage there 
is a division of chromosomes. I am inclined to think there is, but 
the supposed instances of it are not clear enough to enable one to 
come to a final decision. There is undoubtedly a subsequent increase 
in the number of nuclei, but not by karyokinesis. 
The number of eggs in a group varies : comparing the several sections 
of a germling together, I found it to contain twenty nuclei ; in others the 
number would not be more than five or six. 
After a time the several chromosomes in a nucleus become spherical 
in form, then fuse together to form a nucleolus ; at the same time a faint 
reticulum appears (Fig. 40), which very often contracts away from the 
membrane. 
It was stated above that no cytoplasmic radiations were ever associated 
with the multipolar spindles described in the preceding section. Fig. 41 
represents a later stage in which radiations occurred, and where also one 
of the nuclei had a well-formed centrosome and the usual distortion of the 
membrane opposite to it. Whether this is an instance of the formation 
of these structures de novo , or whether we have here one of those not 
