Fig. 21. — Karyokinesis. (Adapted from E. B. Wilson.) 



{From Weismann, " The Evolution Theory.") 



A, resting-phase ; B, chromatin {chr) in coiled thread; C, eight 

 chromosomes {chrs) and two asters formed ; D, chromosomes 

 split and lying in equatorial plane, the two centrosomes [csph) 

 at the poles ; E, chromosomes separate ; F, division of cell- 

 substance ; G, final formation of two daughter-cells; zk, cell- 

 substance ; kk, nucleolus ; km, membrane of nucleus ; aeq, equa- 

 torial plane ; ksp, radiating fibres. 



