320 



BIOLOGY OF THE PROTOZOA 



2 3 



19 



-'&B&'. 



mm 



3fe 



20 



Fig. 162. — Oxytricha fallax; conjugation and meiosis. 2 to 9, formation and divi- 

 sion of the first meiotic nuclear spindle and separation of the twenty-four dumb-bells 

 into two groups of twelve dumb-bells each; 10 to 12, the second meiotic division; 13 

 to 15, the third division; 1G, one of the pronuclei; 17 to 20, the first zygotic division. 

 (After Gregory.) 



