BY THE SWARM-CELLS OF MYCETOZOA. 437 
lately as 1887, still stands in support of his view, and as it 
appears to be a matter of considerable physiological interest, I 
venture to offer the following observations on the swarm-cells of 
Stemonitis fusca and some other species which have come under 
my notice. 
On October 9, 1888, I gathered ripe sporangia of Stemonitis 
fusca, the spores of which were unusually rapid in developing. 
Within an hour and a quarter after placing the spores in water 
under a thin coverslip they began to hateh, and in a couple of 
hours the water teemed with swarm-cells; they emerged in four 
to ten minutes after the rupture of the spore, and in about a 
quarter of an hour the cilium was protruded. Almost imme- 
diately behind the cilium, and occupying the greater portion of 
the conical anterior part of the cell, lies the nucleus, and behind 
this again extends the main protoplasmie substance containing 
minute granules and often several vacuoles. Sometimes only one 
contracting vacuole is observed, but frequently six or seven 
others may be seen, appearing and disappearing at irregular 
intervals. There is continued change of position of the vacuoles 
and the contents of the body of the organism; the nucleus, 
however, always retains its place in the conical end. 
This change of position of the contents varies in character in 
different species; in the large swarm-cells of Amaurochate atra 
there is a remarkable flow suggesting an approach to streaming 
movement, more than the mere mixing together occasioned by 
the spasmodic jogging of those of Stemonitis. 
The rounded posterior end of the swarm-cell is frequently 
seen to broaden out and to extend pseudopodia, either as irre- 
gular projections or as extremely delicate threads. 
On one occasion I had under a square coverslip many hundreds 
of swarm-cells of Stemonitis, which had been hatched two days 
previously, and were in rather a flagging condition. I happened 
to have in a wine-glass of water some pieces of Stereum hirsutum 
which had been soaking for some days, and the water was turbid 
with large bacilli, measuring 3 to 6 a in length. I admitted 
a drop of this water under the coverslip. The bacilli rapidly 
spread among the swarm-cells, which soon appeared to revive 
from their sluggish condition, the jogging movement and the 
lashing of the cilia becoming much more active; at the same 
time I noticed that many had bacilli, in some cases as many 
