ALGAE AND HIGHER PLANTS 



205 



r' 





Fig. V.4. DapAma, anterior end, 200 X . A, brightfield. S, bright-contrast phase. 

 C-E, Pediastrum, 750 X: C, brightfield. D, high bright-contrast phase. E, dark- 

 contrast phase. F-H, nematode head, 100 X: F, brightfield. G, bright-contrast 

 phase. H, high darlc-contrast (B — ) phase. 



