Olive—Cytologioal Studies on Cemtmnyxa. 759 
has in this case reached the surface. Undoubtedly in these in¬ 
stances certain strands have reached the surface and have been 
at once cut up, while still other strands continue for a time 
their creeping movements, finally to reach the surface. Such 
observations clearly differ markedly from those of Famintzin 
and Woronin, who concluded that just before cleavage the pro¬ 
toplasm forms over the surface of the sporophore a more or 
less compact, thin layer, of equal thickness. Again, spherical, 
multinucleated masses, containing a varying number of nuclei, 
often occur. Probably in such instances certain strands 
reached the surface and ceased their streaming movement, 
then became cut up into pieces of irregular size, which at once 
proceeded to round up. I have not yet seen how such frag¬ 
ments are still further cut up into uninucleated pieces. Possi¬ 
bly creeping may again be resumed before cleavage occurs; or, 
it may be that cleavage furrows cut directly into the spherical 
mass. 
Figure 5 illustrates the final constriction of a binucleated 
fragment of the plasmodium. Such a method of simple con¬ 
striction is apparently of common occurrence, since I have ob¬ 
served quite frequently chains of several such Amoebeirlike 
cells connected thus by means of slender isthmuses. Such a 
phenomenon is obviously the result of the cleavage of an ex¬ 
tremely thin strand or filament of protoplasm, which has been 
drawn out to a filament only one nucleus thick. When Figure 
5 is compared with Figure 4, one might at first come to the 
erroneous conclusion that here are represented two quite dis¬ 
similar methods of cleavage. But in reality these figures show 
entire similarity in the essentials of the process. In the in¬ 
stance illustrated in Figure 4, the protoplasmic strand is sim¬ 
ply thicker at the time of cleavage than that shown in Figure 5. 
Such a thick strand could obviously result either from the fail¬ 
ure to creep out to the extreme degree of attenuation; or from 
the massing, or piling up in places of the proto¬ 
plasm of a filament. Further, creeping movements appear to 
be in progress in the late stage of cleavage shown in Figure 5, 
as evidenced by the two cells separating, or pulling apart, after 
the manner of a dividing Amoeba. In some cases, the attenu- 
