3/4 ANDREWS. [Vou. XII. 
formation, and so the two halves become in fact re-united by 
their substance before they are well separated. 
Following hard upon the physical splitting of the mass apart, 
similar spinnings from the newly separated surfaces spring up, 
so close indeed at the heels of the cleavage, that there is often 
scarcely the width of a half dozen such threads between those 
most newly formed and the still fused edges of the cleft. By 
the time the first cleavage is ended, and this does not take 
up many moments, the path of liquid between the sister cells 
is already crossed many times by minute and most delicate ray- 
like extensions, and strands, and even skeins of more tenuous 
threads. 
During succeeding changes of contour, when the blastomeres 
round themselves up and then again flatten, and still again 
become slightly concave in the centre, yet oppose a more or 
less plane surface to each other, the spinnings never cease, 
although the processes are in a state of general instability. 
Under a lower power, even one of 1500 diameters, the filose 
processes are wholly invisible, the surface of the cell presenting 
an optically unbroken surface, which to still lower powers looks 
smooth even. 
While the cells lie opposite one another thus, there is some 
ramifying and divergent spinning among the threads, and anas- 
tomosis of some of the finer secondary filaments, but this is 
mostly near the central, slight hollowing out of the surfaces ; 
those threads having their origin in the more viscous-looking, 
outer portion of this plane tending rather to form bands and 
strands of more refractive and direct character. 
Later, when the cells begin to approach each other, the con- 
necting filaments show a decided tendency to still more marked 
directness, and smoothness, and viscosity of texture. The 
lateral, branching spinning becomes rarer; and as the cells 
approach each other the band and rod-like connecting fila- 
ments become shorter and gain a look of tenseness; and flow 
between the two cells of protoplasm by way of these threads 
was not noticed. 
The threads shorten, and as they shorten become thicker 
and more highly refractive, — that is, certain ones, for some of 
> 
