THE Microscope. 307 
A NOTE ON DIFFLUGIA URCEOLATA. 
H. M. 8. 
BOUT four o’clock one afternoon the field of my microscope 
contained a Difflugia urceolata, Carter, across the mouth of 
whose shell I thought, at first glance, an Amba proteus was 
passing. A higher power objective told another story. The 
Ameba was not wandering past the home of a relative, but was 
coming out of its own front door, and was in visible connection 
with the concealed portions of the owner and inmate. The shell 
was sufficiently transparent to show the passage to and fro of the 
protoplasm and its granules between the exterior Ameba and 
the partly concealed internal sarcode, and to prove that the 
former was but an extension of the sarcodic substance of the 
Difflugia itself, The Rhizopod appeared about to change its 
residence or to undergo an alteration still more momentous. 
The movements of the extruded mass were amceboid and active, 
and its resemblance to Ameba proteus was close, with the except- 
ion of its habit of protruding numerous, short projections which 
gave it a villous appearance, resembling that of Ameba villosa. 
Twenty minutes after it was first seen, the protoplasmic 
current suddenly set in in one direction and poured out of the 
shell, dragging a posterior extremity thickly villous. It was 
then to all appearance a large and active Ameba villosa, and 
would certainly have been so considered had not its exit from 
the shell of the Difflugia been witnessed. It extruded no pseu- 
dopodia, but moved forward by a steady, onward flow of its 
protoplasm. ‘The villous patch was always visible, and a curi- 
ous fact is that by carefully watching this velvety region a 
change in the direction of the Ameba’s movements could be 
predicted before the movement had begun. When the patch 
appeared on the advancing extremity the Ameba at once began 
to move in the opposite direction. It seemed as if the creature 
considered the veivety spot as a cluster of enemies which must 
be avoided. 
About twenty-five minutes after it was first seen, it was almost 
motionless, and the whole body, for the first and only time, be- 
came densely villous. Five minutes later the ectosare became 
remarkably thick and distinct, the endosare showing very slight 
motion. It rested unchanged for about five minutes longer, 
when it resumed its course and continued to wander about the 
