Abstract
1. The prophase chromosomes in the pollen grains of Hyacinthus orientalis var. “Sir William Mansfield” (2x=16) show relie and relational coiling.
2. These kinds of coiling may be in the same or in opposite directions in the two arms, but the direction is generally consistent within an arm.
3. In the nucleolar chromosome there is no evidence of a particular direction characteristic of either arm, but there is a slight positive correlation between the directions of relie coiling in opposite arms. The relational coiling in the two arms appears to be at random with respect to one another.
4. If relic coiling is determined by the internal coils at the previous mitosis and relational coiling to those developing at the present mitosis, then the coiling directions in successive mitoses seem to be indeterminate, and characteristic of individual mitoses, but not of individual chromosomes.
