758 Wisconsin Academy of Sciences, Arts, and Letters. 
contraction of the protoplasmic reticulum, and not by a grad¬ 
ual expansion of the meshwork, as in Ceratiomyxa. 
The cleavage which has taken place to form the uninucleated 
cells shown in Figure 10 requires here a special discussion. It 
will he remembered that, as the cylindrical sporophores grow 
both in length and breadth, the protoplasmic meshwork in each 
creeps gradually to the surface, there to form, according to 
Famintzin and Woronin, a superficial zone of equal thickness, 
composed of more or less compact protoplasm, with small, ir¬ 
regular lacunae. They state that in this condition a simulta¬ 
neous cleavage into uninucleated segments occurs. But their 
one figure illustrating the process (Fig. 11, PI. 2) does not ap¬ 
pear to warrant such an unqualified conclusion, since, while the 
upper portion of the sporophore is shown to be completely cut 
up, the lower part, on the other hand, still contains some pro¬ 
toplasm in process of division. In my own preparations, also, 
there is abundant evidence to warrant the conclusion that the 
cutting up of the protoplasm of a sporophore is not simultane¬ 
ous, but is a progressive process. But the phenomenon in this 
instance undoubtedly takes place very rapidly, and probably 
in much less time, comparatively, than in the case of the thick 
masses of spore-plasm in the aethalia of Fuligo and in other 
forms. 
In Figure 4 is shown a four-nucleated fragment undergoing 
cleavage. Surface furrows have begun to 1 cut the mass into uni¬ 
nucleated pieces. Hear this mass in the preparation are other 
fragments of varying size, which are also partially cut up; 
while in still other neighboring localities, in the same section, 
cleavage is already complete, resulting in a multitude of round¬ 
ed. uninucleated cells, two of which are shown in Figures 8 
and 9. Obviously the protoplasm in one part of a sporophore 
may be thus in a more advanced state of cleavage than in an¬ 
other part. Other instances point unmistakably to this conclu¬ 
sion. For example, in many sections the sporophores show 
some rounded, uninucleated fragments, apparently attached to 
the surface of the slimy axis; while immediately beneath these 
rounded cells occur irregular strands of protoplasm, imbedded 
in the slime. It is plain that only a part of the protoplasm 
