LATTICE WORKERS, OR POLYCYSTINA. 75 



the midst of its gelatinous mass, digests it, and 

 rejects the undigested portions. Now it is almost 

 spherical, then oblong, lengthens itself into a long and 

 narrow body, and then as speedily becomes triangular, 

 starshaped,or many-sided. Every instant changing its 

 form and assuming every shape of which a plastic lump 

 of gelatine is capable. In the simple A mceba, portions 

 are thrust out and extemporised into legs or arms, and 

 drawn back again and absorbed when their work is 

 performed ; but in a 

 slightly advanced ani- 

 mal, called Actino- 

 phrys^ these pseudo- 

 podia, or false arms 

 and legs, are more 

 thread-like and more FIG . ^.ACTINOPHRYS. 



permanent, as they 



are also in the Polycystins. The bulk of the sar- 

 code occupies the interior of the shell, or skeleton, 

 whilst the pseudopodia are protruded through the 

 many orifices, and seem to coalesce at the base,, 

 and flow over the skeleton, so as to form a thin 

 layer like a pellicle enclosing it. By means of these 

 protruding arms the animal not only moves from place 

 to place, but is enabled to procure its food (fig. 14). 



Adverting for a moment to the little animal 

 already alluded to, which is almost as commonly 

 found in fresh-water as the Amceba, and bears a 



