c /l"0 ^^ 



r\ \ 





Plate XII 



No. 16 Mitosis in mouse spleen cell from prophase to anaphase. X 2000 

 (reduction 3/4). (o) Prophase. Nucleoli still present, (b) Very late prophase. 

 5 minutes later than (0). Chromosomes crowding towards asters, (c) 25 minutes 

 later than (a). Metaphase. (d) Anaphase. 29 minutes later than (0). The 

 spindle is nearer the upper margin of the cell, where the cleavage furrow has 

 ■first appeared, (e) Late anaphase. 32 minutes later than (o). Cleavage markedly- 

 asymmetrical. (The further reconstruction of the left-hand group of chromo- 

 somes has been shown in Fell and Hughes*^, Plate VII) 



{Continued on opposite page.) 



