242 
PROCEEDINGS OF SOCIETIES. 
and protruding organs not haying been seen, if they really existed. 
There can be no doubt that they do not. At each extremity of the Clos- 
teria, however, there is a distinct chamber or space containing active 
moving grannies constantly flitting about; what they mean, or what 
their purpose or import, is as yet unexplained. It may be that they 
are merely passively tossed about by the eddy which is likely to be pro¬ 
duced by the conflicting currents of protoplasm, which are so evident 
and so curious in Closterium. But a very similar circulation occurs in 
Penium digitus , but here, notwithstanding the current, there is no open 
clear space at the ends containing moving granules. In that species, 
however, there are moving granules to be seen travelling over the surface 
of the mass of endochrome, which sometimes make their way down the 
frond, at one side, to the end, where they follow its curve and come up 
by the other side, which looks like as if these granules were carried by 
the current, which is, however, apparently of an irregular character like 
that in Closterium. But, again, it is no uncommon thing to see the 
broken-up granular contents of a Closterium pressed-out upon a slide, 
to exhibit the same agitated dancing motion as a few possessed within 
the living frond; and I have seen (it was in Closterium lanceolatum), 
in a specimen from which the contents had nearly all been pressed-out, 
leaving only comparatively a very small quantity within the ruptured 
frond, the (as yet) contained granules flitting about quite like the few 
terminal ones in the normal state. Very little actual change of position, 
however, was effected on the part of any of these granules, except by 
a few which happened to lie at one side of the frond. These were 
(as it appeared to me) guided along by their happening to be in this 
position, and effected sometimes a somewhat considerable onward mo¬ 
tion. The whole thing struck me as forcibly resembling the terminal 
space, enlarged as it were by the' withdrawal of the great mass of the 
endochrome, and only leaving behind enough of the disintegrated cell- 
contents to furnish a somewhat evenly distributed crowd of granules 
moving, their only definite boundary being now the external wall of the 
frond, and not, as in the normal state, a little cavity or chamber, exca¬ 
vated, as it were, out of the endochrome. A very similar movement 
occurred amongst the pressed-out granules, but probably, on the whole, 
not so active as that noticed in the still contained granules. I apprehend 
this phenomenon must have been due to “ molecular motion,” for the 
current even within the frond must have been, of course, wholly destroyed, 
which, even did it exist, would be hardly likely to produce their curious 
dancing motion ; and if the pressed-out contents exhibit motion in obe¬ 
dience to that curious law, I should imagine that the granules normally 
disassociated from the endochrome within the living frond cannot be 
exempt from it, and which may account in some measure, in conjunction 
with the circulation possibly, for the remarkable movement noticed in the 
Closteria. The “ swarming motion” before alluded to as occurring in 
many species may be a movement of a similar nature ; it is, however, 
more vigorous and active than that which is noticeable in the pressed- 
out cell-contents in the ordinary condition. I shall presently advert to 
