6 
INTRODUCTION. 
wall is seen almost immediately to slip free from the protoplasmic 
contents, often with a sudden jerk, and by this action may be 
removed to some distance fi-om the now naked spore, while it 
retains its original form as an empty transparent sac* 
The naked spore remains from six to nine hours without any 
apparent alteration; at the end of this time a slow amoeboid 
change of outline is observed, sometimes accompanied by the 
projection of numerous pointed pseudopodia, and a constriction 
begins to appear in the middle portion. As this continues, a 
second constriction can be noticed in each lialf . The first tUvision 
may now become complete, but usually the whole of the spore 
contents remains united 
until a fm^ther constric- 
tion takes place in each 
quarter, and in about 
an hour from the time 
when the first movement 
was observed the origi- 
nal ellipsoid body is 
divided into eight spher- 
ical portions. These 
occasionally become free 
at this stage, but as a 
rule they continue at- 
tached to one another by 
narrow bridges; a few 
minutes later each pro- 
trudes a flagellum, and 
assumes the pyriform 
figure of a swarm-cell; 
then by the united lash- 
ing movement of their 
flagella the cluster of 
eight swarm-cells swims 
away. They may remain 
connected for an hour 
or more, but eventually 
c to fif. Successive stages in the division of the naked become detached, and 
'T'chistfr of eight swarm-ceiis. resemble in all respects 
Magnified 1200 times. the swarm-cclls of the 
Endosporece. 
The Plasmodium. — The phenomena which are met with in the 
swarm-cell may be seen in the plasmodium on an extended scale. 
Like the amoeboid phase of the former, it is endowed with power 
of locomotion, and advances over the substratum witli a creeping 
movement. The interior substance consists of granular proto- 
* I have not observed the emergence of the sporc-contcnts iu an amoeboid 
form through an oi^erfng of the spore-wall as described by Famintzin and 
Woronin, " Ueber Ci""at'mm hydnoides, Mem. Acad. Petersbourg, " xx. 3, 
1873. 
