134 CURREY, ON STEPHANOSPHARA PLUVIALIS. 
on the Ist of April, 1857, attained a larger size, and the 
protoplasm of the primordial cell, instead of retaining its 
continuous outline, became elongated here and there into 
simple or forked mucilaginous rays, which were either colour- 
less or green from the presence of chlorophyll (fig. 15). 
These rays are probably produced by the protoplasm adhering 
at certain points to the surrounding membrane, and being 
carried outwards by its growth. The Chlamydococcus-like 
form only lasted a few hours: towards the evening the 
zoospores mostly began to divide. In the first place, the 
protoplasmic rays are drawn in, and the primordial cell be- 
comes round; it then elongates itself in the direction of an 
axis passing through the point of origin of the cilia, and by 
the process of division assumes the forms shown in figs. 16 
and 17. This state is usually attained by about nine o’clock 
in the evening, and about eleven o’clock a constriction com- 
mences in a plane at right angles to the former plane of 
division, and eventually the primordial cell is divided imto 
quadrants (fig. 18), each containmg a nucleus and a portion 
of the red substance. The two cilia, which have retained 
their activity, originate in the interspace between two 
quadrants (fig. 18). About midnight usually, but sometimes 
earlier, constriction recommences, and the form in fig. 19 is 
attained. This constriction proceeds towards the middle . 
point of the spheroid, by which the quadrants are bisected, 
and ultimately divided into eight wedge-shaped portions, 
whose contour lines, like the spokes of a wheel, meet in the 
middle. 
And now commences a further process of development, 
which forms the ground of the generic distinction between 
Stephanospheera and Chlamydococcus. For, whilst in Chla- 
mydococcus the individual portions of a primordial cell sepa- 
rate entirely from one another, each developing its own 
enveloping membrane, and ultimately escaping as a uni- 
cellular individual; in Stephanosphzera, on the other hand, 
the eight portions remain united as a family. The coloured 
contents of the individual portions become drawn back towards 
the periphery in a centrifugal direction, a colourless plasma 
remaining about the central point; this disappears at first in 
the centre; a cavity is formed in the middle of the dise, and 
as this enlarges the eight portions assume the form of a 
wreath, consisting of eight globular or ellipsoidal bodies in 
close contact (fig. 20), and usually not exactly in one plane, 
owing to the outer membrane not having expanded in pro- 
portion to the enlargement of the plasma. The original 
cilia continue active, causing the motion of the whole 
