Nou2iy “SPINMING' ACTIVITIES OP  PROTOPLA SIA. 2V7 
traceable in the protoplasm underlying the pellicle, and much 
finer than that found in the more central portion of the mass, 
remained optically undisturbed by these displacements of a 
peripheral substance which formed indeed the so-called pel- 
licular film of the structures of Biitschli. 
In attaining a four-celled stage, the phenomena were prac- 
tically a repetition of the first set described. After fusion, the 
blastomeres rounded themselves up and formed a hollow mass. 
The central cavity of this, which was the “cleavage cavity,”’ of 
course, was filled with a network of interlaced and even anasto- 
mosed filaments. And still the periphery of the now quadruple 
mass spun as before. 
The most active portion of the common periphery seemed to 
be always at the rounded sides of the partial cleft which marked 
the junction of each two, adhering blastomeres. The most 
freely ramifying and anastomosing processes seemed to come 
always from the inner surfaces which lined the cleavage cavity, 
and this portion of the general substance showed greater fluidity, 
which extended inwards some little distance in each cell. 
During the rhythmic cell-flattenings, the very active portion 
of the periphery just mentioned was always most extended and 
flattened, so that under highest powers it showed a decided 
prominence. This, under lower powers, might possibly be seen 
as a slight modulation of the rounded surface-outline. 
Here the filaments attaching themselves to the opposing sur- 
face would seem to pull it somewhat out of place, and here, 
as in the actual cleavage, there was a tendency to formation of 
fusing filaments, or strands and bands. 
So matters continued throughout the cleavage up to the time 
of closure of the opening into the cleavage cavity, over, and 
sometimes within, which the polar bodies lay. 
At all times the cleavage cavity was crossed by a variable 
number of threads, connecting distant cells as well as those 
nearer together; each cell seeming desirous of connection, 
though not persistently, with all other cells. The filaments 
were long, more or less direct, connections which in many 
cases ramified during their course, sending branches to several 
cells, or spinning by the way a network whose filaments 
