28 



BIOLOGY OF THE PROTOZOA 





B 



Fig. 6. — Dileptus anser, two sister cells. A, normal individual; B, individual starved 

 for several days. (From Calkins.) 



Fig. 7. — Uroleptus mohilis Engelm. Old age specimens showing degeneration of 

 macronucleus M and loss of micronuclei. See frontispiece. (After Calkins.) 



