72 COCCOPHYCE. 
parent globe. This process was observed to occupy about twelve hours. 
Cohn also observed the division of each of the eight primordial cells into 
a great number of microgonidia, which swarm within the globe, and 
escape from it. Under certain circumstances each of the eight cells 
secretes a cellular covering, and swims about in the interior of the 
globe in the form of free Chlamydococcus-like cells. Eventually they 
escape either by fissure of the globe or by its gradual dissolution, lose 
their cilia, form a thicker membrane, become motionless, and accumu- 
late at the bottom of the vessel. If the vessel be permitted to become 
dry, and afterwards filled with water, motile Stephanosphera reappear, 
from which it seems probable that the green globes are the resting cells. 
The resting cells vary much in size, and it is supposed that they 
grow considerably after attaining a state of rest. The colour is deep 
green, sometimes yellowish or olive, and they possess a nucleus. 
The dried resting spores absorb water, and their contents gradually 
fill up the cavity of the containing membrane, and become cloudy and 
granular ; the border becomes yellowish, and the red colouring matter is 
contracted in the centre. The cells then begin to divide and pass 
through successive stages, as shown on the plate (Plate 28, figs. 13 
to 17). The four daughter-cells begin to quiver, and endeavour to 
separate from each other. Two cilia are now apparent at the pointed 
extremity of each of the four cells (fig. 19), by the action of which the 
group begins to move as a whole; utlimately all trace of the enveloping 
membrane disappears, and one by one the daughter-cells escape and 
become free. At the moment of escape their diameter never exceeds 
‘Ol mm., but they soon enlarge to a diameter of ‘013 to ‘015 mm, 
The length of time which elapsed between the immersion of the 
dried resting spores and the first appearance of the motile cells varied 
from nine to twenty-four hours. It was observed that those resting 
spores which did not produce zoospores within six days never did so 
afterwards, although they continued to live, and seemed perfectly 
healthy. Zoospores produced in November did not advance beyond the 
first stage. Others produced in March remained only a few hours in 
that condition, after which time a delicate membrane was formed 
round the body of the primordial cell; this membrane was at first 
closely attached to the cell, but became gradually enlarged, by absorp- 
tion of water, into a colourless enveloping vesicle, usually globular, 
but sometimes oval, having two openings, through which the cilia 
penetrate. In this condition they attain a diameter of ‘017 to (022 mm., 
and are not distinguishable from encysted forms of Chlamydococcus 
pluvialis. Other zoospores, produced in April, attained a larger size, 
and the protoplasm of the primordial cell, instead of retaining its con- 
tinuous outline, became elongated here and there into simple or forked 
mucilaginous rays, which were either colourless or green from the presence 
of chlorophyll. These rays are probably produced by the protoplasm ad- 
hering 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. 
The rays are drawn in, the primordial cell becomes round, it then elon- 
gates, is constricted, and ultimately is divided into four quadrants. 
These are again bisected, and eventually eight wedge-shaped portions are 
formed, whose contour lines, like the spokes of a wheel, meet in the 
middle. 
Here is to be noted a distinction between the Stephanosphera and 
Chlamydococeus ; for while in the latter the individual portions of a 
primordial cell separate entirely from each other, each developing its own 
enveloping membrane, and ultimately escaping as a unicellular indi- 
vidual, in the former the eight portions remain united as a family. The 
