44 ACTINOPHRYS. 



This figure (fig. 22) represents the internal structure of Acti- 



nophrys, the typical genus of this group. It abounds in still 

 waters and ditches, from whence it may be collected and pre- 

 served alive by skimming the surface of the soft silt, and deposit- 

 ing it, for observation, in a glass jar of clear water taken from the 

 same spot. Even to the naked eye it is visible as a distinct, 

 white, glistening spot, apparently about as big as a pin-hole. Un- 

 der a moderate magnifier it resembles a small sun with greatly 

 prolonged rays. It is on this account that one of the species has 

 been called Sol. Although, as we shall see presently, capable 

 of moving parts of its locomotive apparatus with great rapidity, 

 it progresses at a very slow pace, balancing itself on the tips of 

 its rays (ps), which project from all sides of the body. In fact, 

 it is so sluggish that it may be handled, with a great deal of 

 freedom, without inducing it to retract its pseudopodia (ps), as 

 its rays are called. Notwithstanding that the pseudopodia are 

 capable of being totally contracted, so as not to leave a trace of 



Fig. 22. Actinophrys Eichornii. Ehr. 130 diam. A view of the interior, as 

 if it had been cut open at the middle. ps, the pseudopodia acting as organs of 

 locomotion and for prehension ; r, living prey, a Rotifer, just caught ; r l , another 

 Rotifer in the process of engulfment ; cv, the contractile vesicle, one of the cells 

 of the outer layer. Original. 



