Crossword puzzle clue "fall into rows"

One who rows, rows, rows the boat

Web concerns ... and based on six familiar names hidden in rows 1, 4, 12 and 15 of this puzzle grid, what the black squares in those rows symbolize

Rows of rows

Fall into rows

It may be divided into rows

They get into rows at school

Put into rows

Whence the line "Into the eternal darkness; into fire and into ice"