Ig] CELL AND NUCLEAR DIVISION IN FULIGO VARIANS 223 
be compared to the cleavage from vacuolar surfaces as I have 
described it in Pilobolus (4). 
As noted above, the first cleavage furrows commonly do not 
cut through the entire mass of protoplasm in which they are 
formed, but curve and fork so as to cut off one or more super- 
ficial layers of segments. Further furrows, not continuous with 
the first, then cut through the central mass, dividing it up into 
large blocks, each with many nuclei. Meanwhile the superficial 
segments have still further divided, so that we regularly have 
one or few nucleated masses at the surface, while the central 
protoplasm is relatively undivided. The segmentation is very 
peny.» progressive process proceeding from the periphery 
toward the center. There is no such thing as a simultaneous 
breaking up of the protoplasm into uninucleated fragments. The 
protoplasm which thus segments is quite homogeneous, as noted 
“ove. There is no differentiation of hyaline zones or other 
peed regions prior to the formation of the cleavage furrows. 
Furthermore, the nuclei show no special distribution about the 
tleavage planes. As seen in figs. z and 2, it is quite common to 
find a group of nuclei on one side of a cleavage furrow while 
— oe dead a considerable area on the opposite side. 
any fee indication whatever at this stage that the nuclei exert 
influence on the orientation of the cleavage planes. 
‘we examine the protoplasm immediately in front of one of 
any > diag pitrows also, we find it without differentiation of 
will one et ag indicate the direction which the furrow 
to advance al ide from the fact that it is common for the tiie’ 
it is quite 8s the same plane or curve in which it has ~~ : 
OW, i. ¢ « scgeateesheg predict in the case of any yer e 
in which Mic which has not yet cut through the protop si 
able that iy sas direction it will take. It is very notice 
Which is se x ates currows do not necessarily cut the pn 
through RoR one through its shortest axis, any more : . 
Cut off oar & = It is very common to see a strip or Ss - 
Plane of ag ae of 4 larger mass in such a fashion that : 
age lies in the long axis of the mass which is 
thes 
