Fig. 23. Chlamydomonas . A, C. angulosa, x 1000. B-D, the same, in fission 

 (radial). E-H, C. longistigma in fission (pseudo trans verse). Highly magnified. 

 After Dill,' with modifications, c.vac. contractile vacuole; cph. chromato- 

 phore; cu. cuticle; e. eye-spot; nu. nucleus; pyr. pyrenoid. 



Fig. 24. Polytoma iwella, x about 1300. A, Ordinary individual, showing 

 nucleus, eye-spot, contractile vacuoles, flagella w^ith basal granules, and starch 

 grains, the latter confined to the hinder part of the body. B-E, stages of the 

 first fission. In C and D the flagella are omitted. Highly magnified. After 

 Dangeard, 



