760 Wisconsin Academy of Sciences, Arts, and Letters. 
ated strand connecting the dividing cells persists nntil it be¬ 
comes stretched out to a length equal to two or three times the 
diameter of the cells. But in such a thick strand as that 
shown in Figure 4, the narrow cleavage furrows indicate 
that the creeping movements have, on the other hand, appar¬ 
ently ceased entirely. I have no evidence as to whether or not 
the furrows in such instances become broader during the later 
stages of the process, thus evidencing the resumption of the 
creeping movements before cleavage is finished. 
It is apparent from the above description that cleavage oc¬ 
curs at the end of a comparatively long period of active up¬ 
ward movement of the fructifying reticulum. During this 
period of growth, the strands become in general more and more 
attenuated, and at the same time the whole reticulum moves 
to the periphery of the sporophore. Cleavage therefore occurs 
at the culmination of the upward growth of the sporophore; 
apparently only when the strands, either in a state of extreme 
attenuation (Fig. 5) or in thicker masses (Fig. 4), have 
reached the periphery of the gelatinous axis which forms the 
slimy, watery substratum through which the protoplasm has 
crept. 
As stated above, cleavage may be at a given moment more 
advanced in one part of a sporophore than in another part. 
The process sometimes varies similarly in a group of sporo- 
phores, although, in general, contiguous sporophores are usual¬ 
ly at about the same stage of maturity; while those farthest 
separated in the group are, on the other hand, apt to differ 
widely in their degree of advancement. 
Although poorly stained in the preparation, the nuclei shown 
in the uninucleated cells of Figure 10 appear to be, when ex¬ 
amined closely with high power, strikingly large and conspicu¬ 
ous. Such a condition is much better shown in Figures 6-0. 
In the preparation from which Figures 6-9 were drawn, hun¬ 
dreds of similar rounded cells lie in each section of the series, 
although there are also a few multinucleated fragments, such 
as are shown in Figure 4, which have not yet been completely 
cut up. Such a preparation represents the condition of the 
protoplasm near the close of cleavage; while in Figure 10, 
