RHIZOPODS. 123 



broken by the cover-glass or otherwise injured, when it 

 will at times creep out and die. I have observed 

 across the mouth of the shell of Difflugia urceolata what 

 I at first thought to be an Amoeba proteus which seemed 

 to be passing. A higher-power objective showed that 

 the Amoeba was not wandering past the home of a rel- 

 ative, 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 pro- 

 toplasm and of its granules between the exterior 

 Amoeba and the partly concealed internal sarcode, and 

 to prove that the former was but an extension 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 Amoeboid and active, and its resemblance 

 to Amxba proteus was close, with the exception of its 

 habit of protruding numerous, short projections which 

 gave it a villous appearance, resembling that of Amoiba 

 villosa. 



"Twenty minutes after it was first seen, the proto- 

 plasmic current suddenly set in toward one direction 

 and poured out of the shell, dragging the posterior ex- 

 tremity thickly villous. It was then to all appear- 

 ance a large and active Amaba villosa, and would 

 certainly have been so considered had not its exit 

 from the shell of the Difflugia been witnessed. It ex- 

 truded no pseudopqdia, but moved forward by a steady 

 onward flow of its protoplasm. The villous patch was 

 always visible, and an interesting fact is that by care- 

 fully watching this velvety region a change in the di- 

 rection of the Amoeba's movements could be predicted. 



