106 LIFE PHENOMENA .’ SOME NOTES ON NITELLA, ETC. 
press firmly upon the cell, and the current, which was 
flowing so actively and with such regularity, will at once be 
partially, or it may be wholly, suspended ; remove now again 
the needle, and gradually the current will be seen to resume 
its former activity, and circulate freely; this mechanical 
pressure does not produce any irritable movements. Bring 
now the scalpel to bear upon it, cut the delicate cell into 
two halves, and you will have an observation brought to 
view of exceeding worth and value—an observation which 
will enable you to fully realise and see this fact (which has 
before been alluded to), that the circulatory phenomena in 
Nitella is in reality and without doubt effected alone by the 
active transparent protoplasm, although its movements 
may not have been before demonstrable to you by your 
microscope. To the uninitiated prior to this division of the 
cell, the cell masses must have been themselves accepted as 
the only moving contents; now, however, these masses or 
cell bodies will be noticed to be stationary, and devoid of 
active life movement, while the liquid mass of living 
protoplasm is distinctly to be observed as active and possess¬ 
ing movement. 
Immediately upon cutting through the cell a sudden rush 
of the protoplasm will be observed, and along with it a goodly 
host of the cell masses and granular contents. These latter 
are jutted or shot out to a tolerably good distance, whilst the 
transparent, glairy, tenacious fluid, appearing absolutely 
homogeneous and entirely devoid of structure—the pro¬ 
toplasm—will be found more generally encircling and 
protruding a short distance from the cut surface. Freed 
from its cellulose imprisonment we might naturally expect 
an extensive rush and protrusion, but this is not so; only 
some small portion of what the cell must contain may be 
seen to be protruded, and in some instances I find you may 
only get the protrusion from the one cut surface, the protru¬ 
sion probably coming away from the most heavily charged 
portion. The protoplasm gushes out with active, jerky 
movements, flows in rather a broad stream, and presents a 
slightly rippled surface; these irritable, rippling, jerky 
movements may continue for the space of one minute, less 
or more, and then they cease. The filmy-looking mass 
becomes now quite stationary, and takes on a coagulated 
appearance. Coagulation may set in almost immediately on 
protrusion in some instances. The other escaped bodies 
consist of large circular masses of protoplasm, and other 
smaller circular portions of the same. These showed no 
signs of movement. The chlorophyll masses are to be seen 
