i8 



NORMAL HISTOLOGY. 



(8) The daughter-stars, or diaster, each of these corresponding 

 to a new nucleus. About this time the cell-protoplasm, which until 

 now has been almost passive, begins to exhibit a constriction of its 

 body, which impression now steadily progresses until the protoplasm 

 of the cell completely separates into the portions destined to become 

 the bodies of the cells, enveloping the new nuclei. The karyokinetic 

 cycle is completed by each 



(9) Daughter-wreath or star in turn assuming 



(10) The stage of the daughter-skeins, at first loose and afterwards 

 close; on obtaining nuclear membranes and the nucleoli reappearing, 

 the new nuclei finally pass into the stage of rest. 



FIG. 10. 



Diagram illustrating the migration and redisposition of the segments of chromatin, guided by the achro- 

 matic lines : A, mother-star; B and C, stage of equatorial plate ; D, daughter-stars. (After Rabl.) 



In recapitulation, the above changes may be tabulated as follows: 

 Resting Mother-Nucleus : the inauguration of the changes 

 leading to division are marked by increase of chromatin, 

 resulting in the formation of 



1. The Mother- Skein (Spirent): 



a. Close skein, 



Disappearance of nucleoli. 

 Disappearance of nuclear membrane. 



b. Loose skein, 



Separation of skein into segments. 



Appearance of polar field. 



Rearrangement of segments around polar field to form 



2. The Mother- Wreath, or Aster : 



Appearance of nuclear spindle. 



Longitudinal cleavage of chromatin segments. 



3. Migration of Segments (Metakincsis}: 



Segments pass towards the poles of the new nuclei. 

 Equatorial plate produced by massing of migrating seg- 

 ments. 



