cyroLOGY 6-36 



After a while, one nucleolus takes on the volutin stain, followed 

 shortly by the other, or both fuse. At the same time, the color 

 disappears from the chromosomes or becomes very much dimin- 

 ished. When the bud is growing at its most rapid rate, the nucleo- 

 lus is swollen and densely stained, showing that it contains a large 

 quantity of volutin. The chromosomes are visible as small, faintly 

 stained peripheral bodies on the inner wall of the nuclear vacuole. 



m 



% 



m 



«r 



\ #^P% 



Fig. 6-26 The large spherical nucleolus in the center of the 

 vacuole has taken the volutin stain and chromosomes are visible at 

 the inner periphery of the vacuole or attached to the nucleolus. 



The nucleolus is usually visible as a stained structure only in the 

 vacuole of the mother cell, but in some cases the vacuole of the 

 daughter cell also contains a stained nucleolus. After division has 

 ceased, the nucleolus retains a dense coating of volutin for some 

 time, while the chromosomes are lightly stained. On aeration the 

 volutin disappears from the nucleolus but the chromosomes become 

 coated as in fig. 6-25. 



