40t 



o o 



Diestrus \ ^,thout Colchicine 

 Esirus f 



10.00 11.00 12.00 13.00 14.00 15.00 16.00 



Time of day 



Fig 9 6— Mitotic activity, as demonstrated by colchicine, in the epidermis of the ear 

 of female mice, in estrus and diestrus. Controls: dotted lines. The far greater increase 

 observed after colchicine during estrus is considered to be an indication that normally 

 epidermal mitoses last longer in diestrus. (Modified, after Bullough, 1950" ) 



