I know of no case better adapted to show the importance of the laws of correlation in modifying important structures, independently of utility and, therefore, of natural selection, than that of the difference between the outer and inner flowers in some
Compositous and Umbelliferous plants.
millefolium were found to be compositous, that is, echinate and tectate with spiny exine and 3 pores.
millefolium indicating that fragments of leaves, small flower heads, and stem pieces are visible, while microscopic characters include trichomes long, uniseriate, with pointed terminal cell, glandular trichomes compositous, with about 4 pairs of cells.