EG. 39. Euglena viridis. A, view of free-swimming specimen showing de- 

 tails of structure ; B, another animal showing change of shape and stria- 

 tions ; C and D, outlines showing stages of contraction ; E, reproduction 

 by longitudinal fission ; F and G, division within a cyst: am., pyrenoids 

 with sheaths of paramylum ; chr., chromatophors ; c.v., contractile 

 vacuoles ; e., stigma; m., mouth; ., nucleus; r., reservoir. (A-D 

 from Bourne ; E-G. from Bourne after Stein.) 



