GENERAL CHARACTERS 



45 



posterior end, twisting to the right and left, and so on (Fig. 

 5, A D). These movements are so characteristic of the 

 genus that the name euglenoid is applied to them. 



FIG. 5. Euglena viridis. 



A u, four views of the living organism, showing the changes of form 

 produced by the characteristic euglenoid movements. 



E, enlarged view, showing the nucleus (nu}, reservoir of the con- 

 tractile vacuole (c.vac}, with adjacent pigment spot, and gullet with a 

 single flagellum springing from it. 



F, enlarged view of the anterior end of E, showing pigment-spot 

 (t>g) and reservoir (c. vac\ mouth (m), gullet (ce. s), and origin of 

 flagellum (/). 



G, resting form after binary fission, showing cyst or cell- wall (n/), 

 and the nuclei (nu) and reservoirs (c. vac} of the daughter-cells. 



H, active form showing contractile vacuole (c. vac], reservoir (r), 

 and paramylum-bodies (p}. 



(A G, after Saville Kent : H, from Biitschli after Klebs.) 



The body consists of protoplasm covered with a very 

 delicate skin or cuticle which is often finely striated, and 

 is to be looked upon as a superficial hardening of the 

 protoplasm. The green colour is due to the presence of 



