ORIGINAL COMMUNICATIONS. 
On STEPHANOSPHERA PLUVIALIS. Condensed from the Ger- 
man of Professors Coun and Wicuura, in ‘ Nova Acta,’ 
vol. xxvi, Part 1. By Freprerick Currey, Esq., M.A., 
F.L.S. 
Stephanosphera pluvialis was first observed by Cohn, in 
1850, near Hirschberg, and described in Siebold and Kolliker’s 
‘ Zeitschrift,’* vol.iv, part 1. It consists of a hyaline globe, 
containing eight green primordial cells, arranged in a circle 
in its equator. The globe rotates upon an axis perpendicular 
to the plane in which the primordial cells are arranged, and 
moves actively in space by the aid of cilia, two of which pro- 
ceed from each of the primordial cells, and pierce the hyaline 
envelope. 
The primordial cells divide first into two, then four, and 
lastly into eight portions ; these portions separate from each 
other in a tangential direction, thus forming a dise round 
which a cellular membrane is developed. Two cilia are pro- 
duced upon each segment, and thus eventually eight young 
Stephanospherze are formed, which eventually escape by 
fissure of the parent-globe. This process was observed to 
occupy about twelve hours. Dr. Cohn has 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 Chlamydomonas-like cells. Even- 
tually they escape, either by fissure of the globe or by its 
gradual dissolution, lose their cilia, form a thicker membrane, 
become motionless, and accumulate at the bottom of the 
vessel. If the vessel be then permitted to become thoroughly 
dry, and afterwards be again filled with water, motile Stepha- 
nospherz reappear, from which it seems probable that the 
green globes are the resting-spores of the plant. 
In the Hirschberg habitat the Stephanospherze occurred in 
company with Chlamydococcus pluvialis, the resting-cells of 
which are with difficulty, if at all, distinguishable from those 
* Translated in ‘ Annals of Nat. Hist.,’ vol. x, pp. 321, 401. 
VOL. VI. i 
