c 



Figure 6. Examples of ternary and quartemary I-cell divisions (Sussman 

 et ah, 1960). a. An I-cell yielded four daughters by two rapid, sequential di- 

 visions. One of the divisions was unequal and produced daughters of dispar- 

 ate size. b. Two rapid, sequential divisions of an I-cell which yielded four 

 equal-sized daughters, c. A quarternary fission which yielded four equal- 

 sized daughters, d. A ternary fission. The division at first appeared to be 

 quarternary, but one of the fissions was abortive and the two halves remained 

 as one cell. 



