Marquette—Spore Mother-Cells of Marsilia. 
91 
a much earlier stage in the growth of the cell than is commonly 
the case. 11 Speaking in terms of current theories, the possi¬ 
bility suggests itself that at this stage the pairing of the homol¬ 
ogous chromatin elements may take place, while the subse¬ 
quent contraction and specific orientation of the chromatin 
strands is associated wdth the mechanics of spindle-formation, 
i. e., with the relation between spindle-fibers and chromatin; 
and that in this latter conception may lie the explanation of 
the specific orientation of synaptic masses in general. This 
specific orientation is as conspicuous as the contraction of the 
chromatin at this period and is quite unaccounted for on the 
basis of the theories which find in synapsis a provision for the 
pairing or fusing of homologous chromatin elements. How¬ 
ever, further knowledge of the behavior of the chromatin at 
this time is needed as a basis for such suggestions. The possi¬ 
bility is not excluded that the early contraction in the spore 
mother-cells of Marsilia may be artifact, although it is too reg¬ 
ular in its occurrence to make such a supposition probable. Fcr 
the present, I shall continue to speak of the later aggregation 
as synapsis; but it is to be noted that this is preceded by a 
“spirem” stage! 
As the chromatin passes out of synapsis and becomes more 
uniformly distributed through the nuclear cavity, the fibrous 
constituents of the cytoplasm become even more conspicuous 
and usually show r a tendency to be arranged in cone-shaped 
groups of which there are frequently two in a cell. At times 
a w r ell formed bipolar spindle is developed, the spindle usually 
lying somewhat tangential to the nucleus (Figs. 5 and 6). 
Usually this “spindle” lies on the side of the nucleus adjacent 
to the starch mass. Strasburger 12 figures a similar stage for 
M. elata, and there the same relations seem to obtain between 
the position of the nucleus, the spindle, and a dense region of 
11 Generally in the higher plants the nucleus has reached about half 
or more of its definitive size (linear) by the time of synapsis, although 
there are exceptions, as in Galtonia according to Miyake [ Jahrb , f. 
wiss. Bot., xlii (1906), PI. Ill, Figs. 6-12], In the case of the primary 
oocyte in animal cells, there is of course usually a tremendous in¬ 
crease in the size of the nucleus after synapsis. 
12 Apogamie bei Marsilia . Flora, xcvii, PL VI, Figs. 71 and 72. 
