182  CURREY, ON STEPHANOSPHERA PLUVIALIS. 
of Stephanosphera. In the county of Glatz, however, Cohn 
found another habitat where the Stephanosphera was pro- 
duced without Chlamydococcus, and accompanied only by 
the red Rotifer, Philodina roseola. 
About the same time Wichura found a dark red crust 
covering some depressions on the surface of the mica- 
schist rocks at Quickjock, in Lapland. Upon moistening this 
crust Stephanospherz were produced, mixed, however, with 
Chlamydococcus. 
Afterwards Cohn and Wichura joined in a series of obser- 
vations on the water from Heuscheuer (county Glatz), the 
results of which form the subject of their paper. 
This water was placed (at the end of August) m vessels 
of common glass, green glass, &c., so as to test the effect 
of light. Im the darker vessels the primordial cells re- 
mained delicate, small, and distant from one another, whilst 
in the transparent vessels they grew much larger; and as the 
hyaline enveloping membrane did not extend in proportion, 
the green cells eventually came in contact with one another, 
and became spindle-shaped, with protoplasmic elongations. 
(Ply TN, fis...) 
After eight days the specimens grown in the transparent 
and dark vessels respectively, differed so much from one 
another that they might have been taken for different 
species. 
The size of the resting-spores varies very much, and it 
seems probable that they grow considerably after attaining a 
state of rest. Their colour is deep green (occasionally 
yellowish or olive), and they have a nucleus, and frequently 
a nucleolus. 
When the water is permitted to evaporate gradually, the 
resting-cells become yellow, and afterwards orange or red, 
aud their contents have a more oily appearance. The authors 
found that if the water was not permitted to evaporate, the 
resting-spores, although continuing to live, did not become 
developed into Stephanosphzerz, but when fresh water was 
poured upon desiccated resting-spores twenty-four hours 
sufficed for the production of motile Stephanospheeree. — 
The followmg is the process of transformation from the 
state of rest into the motile form. 
The dried resting-spores take up the water, and their 
contents (hitherto somewhat misshapen) gradually fill up the 
cavity of the containing membrane, and become cloudy and. 
granular (fig. 2); the border becomes yellowish, and the red 
colouring matter is concentrated in the centre. The cells 
then begin to divide, and the successive forms assumed in 
