KING: CYTOLOGY OF ARAIOSPORA PULCHRA. 
in the formation of the peripheral vacuoles may be seen between 
them (pi. 12, fig. 11). At this time, or slightly later, important 
changes take place in the interior of the oogonium. Instead of the 
uniformly coarsely vacuolate condition heretofore observed, there are 
now early stages in the formation of cytoplasmic patches in which 
the meshes are distinctly finer. This is the first indication of the 
development of the fine meshed, central ooplasm which corresponds 
to the “ coenocentrum ” of Stevens and the “ central body ” of Wager 
although in structure it is unlike either. Figure 11 (plate 12) rep¬ 
resents a section through the oogonium at about this stage; in this 
section a few of the fine meshed patches show distinctly. As the 
development of the oogonium proceeds, these gradually increase in 
size and number, are better differentiated, and are seen to be scat¬ 
tered in the interior of the oogonium. In the section represented in 
figure 12 (plate 12) at least nine of these patches may be seen, each 
still retaining its definite mesh-like character. Figure 13 (plate 12) 
is drawn from an older oogonium in which the patches are moving 
toward the center where they are already in early stages of fusion. 
Figures 14,16 (plate 12), and 18 (plate 13) represent stages in which 
the scattered patches have completely fused into one distinct, fine 
meshed mass. Throughout these changes the fine mesh-like charac¬ 
ter persists. It can be seen distinctly when the structures are iso¬ 
lated, when they are fusing, and finally, when they have formed the 
characteristic, irregularly shaped central mass. 
There is considerable variation in the size of the meshes of dif¬ 
ferent patches of the same oogonium. Usually, however, the 
meshes in the isolated and fusing patches are finer than those of the 
later formed, central mass. An examination of figure 18 (plate 13) 
will show that this is not always the case. During their entire 
history they take the stains more deeply than does the undifferen¬ 
tiated ooplasm. This is particularly true of the central ooplasm 
which during its highest development is a very conspicuous structure 
of the oogonium. In fact, it frequently stains so deeply as almost to 
obscure the one or two nuclei that it contains. Whether this deeply 
staining property is due wholly to the fact that there is simply an 
accumulation of more mass here is not clear. It is, however, 
entirely probable that the material in this mass has a greater attrac¬ 
tion for the stain than that of the peripheral ooplasm. 
So far as is known to the writer, the only phenomenon that is 
