THE CHROMOSOMES 181 
pollen mother cells 72 chromosomes (Fig. 47B, c). 
Both of these giant plants were larger than the 
normal plant; they grew more vigorously and all 
of the cells were larger. The difference in size 
extends to the flowers, to the pollen, stomata, 
trichomes, etc., and even the starch plastids are 
larger. This latter condition seems anomalous, but 
Winkler states that even in normal plants the size 
of these plastids varies with the size of the cells 
containing them. 
