RHfZOPODS. 



119 



drop off, especially if the Rhizpod is not in a healthy 

 or a comfortable condition. 



When food is to be taken into the body, a part of the 

 surface with the adherent spines is lifted up, carrying 

 these ornaments to one side, and a wave of proto- 

 plasm, the body substance, flows out to receive and to 

 surround the food brought toward it by the pseudo- 

 podia. It is drawn into the body, the surface closes, 

 and the spines again cover the spot. This may hap- 

 pen at any part of the surface. 



Acanthocystis is often found among the leaflets of 



Myriophyllum, the roots of Lemna, or floating freely 



in quiet water. It is rarely found in the mud, and it 



seems to be more fond of the sun than most Rhizo- 



■pods. : 



4. Actin6phrys sol (Fig. 95). 



This is one of the commonest of aquatic microscopic 

 animals. It may be found floating in every quiet pond 

 and pool, or among the leaflets of nearly everygather- 

 ing of water-weeds. Its 

 body is usually colorless and 

 almost transparent, seem- 

 ing to.be formed of a collec- 

 tion of •small bubbles- so 

 that it has a foamy appear- 

 ance, and it alwiys bristles 

 with numerous long, fine- 

 rays springing -frorti the 

 Whole surface. It moves in 

 a slow, gliding way which 

 has not been satisfactorily 

 explained, but which can hardly be produced by the 

 hair-like rays, for they are motionless, and apparently 



Fig. 95. — Actin6phrys sol. 



