Plate 29. — Changes in a Cell During Mitosis. (Modified from Stras- 



burger, Noll, Schenck, Karsten, " Text Book of Botany ".) 



No f Nucleolus. N, Nucleus. P, Polar caps. C, Chromosomes. PB, Polar 

 bodies. S, Spindle fibers. Z, Cell plate. A, Separation of chromosome loops by 

 traction fibers of the spindle, a and b are halves of a chromosome loop. 



75 



