

Fio. 1. Amoeba polypodia in the successive stages of division. The light spot is the contractile 

 varuole, the dark the nucleus (after F. E. Schulze). 



Fio. -2. A. Quadrula symmetrica, after F. E. Schulze. /;, Hyalosphenia lata, after F. E. 

 Schulze. C, Arcella vulgaris, after Hertwig and Lesser. D, Difflugia pyriformis (after Wal- 

 lich) completed. 



