14 
tlie appearance in the fold of a form very similar to tlie one with 
•which we were so long familiar, but manifesting an entirely dis- 
similar behaviour. 
“ The new comer was, roughly speaking, like the old form in shape 
and size, but instead of two flagella at one end, it had a single 
flagellum at each end, and it was multiplying with great rapidity. 
Reasoning from what we knew, we felt assured that this was not a 
capricious development of our old friend, whose life history we 
had almost compassed.” 
The form above mentioned was carefully watched, and fission was 
found to take place in the following manner. The first indication 
that it was about to take place was that the body became squarer, 
more plastic, and subama3boid ; a slight but sudden constriction 
of the sarcode ensued, which gi'adually increased ; at the last stage 
a stretching of the constricted part of the sarcode took place, the 
flagella lasliing Avith great force. As the sarcode stretched it 
became finer, no more being extended from the now perfectly 
divided bodies, having reached its final length, the attenuated 
sarcode suddenly snaps. Taking an average of forty cases they 
found that this entire process was coinpleted in about four minutes 
and forty seconds. The observers found that this mode of increase 
might continue without any change, for eight days at least. 
Many of the organisms in question all at once appeared to be 
pouring out a delicate sarcode, nevertheless they moved with 
great freedom, the flagella rapidly vibrating, the sarcode increasing 
in size all round the organism, but Avas of extreme tenuity. In 
the course of seven hours there Avere several in the field moving in 
all directions, and at length tAvo touched each other. A rapid 
blending of the sarcode now ensued, and the flagella disappeared ; 
they were constantly watched, the amseboid sarcode of each blended 
Avith the other, and at length the bodies touched and began to 
unite. Their union Avas noAv rapid, and at lengtli they became a 
mere cyst — Avith a very decided investment. Having reached this 
condition and become slightly yellow in hue, an apparent thinning 
of the integument of the cyst ensued. It became suddenly rent aU 
round, and retracted towards the centre. Up to this time they had 
