f»9 
which was, as the following description will show, a shell-less 
fresh-water member of the Radiolaria. 
The most careful investigation was at first attended with 
but little gain ; nevertheless, the mass of sarcode presented 
at first one, and afterwards several, green globules, which 
varied somewhat in size; as the number of these globules 
was constantly two, four, eight, or sixteen, processes of divi- 
sion So frequently observed in similar instances were indi- 
cated. In these creatures could be recognised a dark double 
contour of integument, which enclosed the green globules ; 
within this was discovered a mass of nuclei, which at one 
part, namely at that lying close to the inner surface of the 
membrane, appeared of a green colour, and at other parts 
was colourless ; this presented a very dark contour, refracted 
the light strongly, and varied somewhat in extent. About 
the green globules w T as next presented a broader border of 
sarcode — that delicate, extremely fine, and ever-moving 
substance which consists sometimes of mucous elements, some- 
times of very fine, tortuous, and intercrossing lines, with 
granules scattered here and there between them. From this 
layer of sarcode start up pyramidal tongue-shaped processes, 
and very fine spiny threads composed of the same substance, 
and always placed at right angles to the tangents of the 
spherical body, from which they radiate in all directions. 
As these long processes end in extremely fine points, and are 
constantly extended and retracted, thus probably causing the 
movements of the whole mass, their actual limits may be the 
better determined the smaller the magnifying power employed, 
since with powerful objectives their points are removed too 
rapidly from the adapted focus. The pyramidal tongue- 
shaped processes without doubt take part in these movements, 
since they can be seen to arise and disappear ; their move- 
ments, however, seem to be slower, but cannot be satisfactorily 
investigated in consequence of the general commotion. 
The different parts of such an organism, so far as they can 
be optically determined, might, then, be reckoned from within 
outwards as follows : 
1. The centre of the sphere is filled by colourless plasma 
strewn with granules varying in size, which in itself, or in 
consequence of the presence of the very broadly and darkly 
contoured granules, refracts the light strongly on, or appears 
brighter than, the surrounding water. This contrast is 
presented most distinctly before the focus is closely adapted, 
and when the details cannot yet be recognised with precision. 
2. In the outer portion — that lying close to the including 
membrane — of the plasma which is strewn with colourless 
