INFUSORIA. 149 



10. ASTASIA (Fig. 117). 



Body long and narrow, very soft, and changeable in 

 shape, altering its form as it glides over the slide, which 

 it does quite rapidly. It has one long straight flagellum 

 at the front. It is quite common. 



Fig. 117. Astteia. Fig. 118. Euglena. 



11. EUGLENA (Fig. 118). 



Body long and rather narrow, being widest in the 

 middle and tapering to both ends. It is very change- 

 able in form, and bright green or red in color. The 

 front end is seen witli a high power to be notched as 

 if the Infusorium had two lips, the long, vibrating, and 

 colorless flagellum appearing to issue from the notch. 

 There is sometimes a small red spot near the front end, 

 supposed to be an imperfect eye. It is often absent in 

 an old Euglena. At the posterior end is a short, point- 

 ed, stiff, and sometimes curved tail, which is usually col- 

 orless. The Infusorium is common, occasionally occur- 

 ring in such immense numbers that it tinges the water 

 green. There is another species, or another variety of 

 this species, whose body is bright crimson. It also is 

 so abundant at times that it colors the water blood red. 



12. CHILOMONAS (Fig. 119). 



This colorless little creature is very common in vege- 

 table infusions. It may be recognized by the notch at 

 the widest or front end, and the curve of the back 



