FIG. 22. Euglena viridis. A, view of free-swimming specimen showing 

 details of structure; B, another animal showing change of shape and striations; 

 C and D, outlines showing stages of contraction; E, reproduction by longi- 

 tudinal fission; F and G, division within a cyst; am, pyrenoids with sheaths 

 of paramylum; chr, chromatophores; c.v, contractile vacuoles; e, stigma or 

 eye-spot; m, mouth; n, nucleus; r, reservoir. (A D, from Bourne; E G 

 from Bourne, after Stein.) 



