This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
Popular and showy hardy annuals easily raised from seeds, in which florists do a fairly good trade in spring. Plants raised early in gentle heat, and pricked out into shallow boxes, also sell for bedding in early summer. There are several kinds, such as insignis, 1½ ft., with blue, white, purple, rose, and striped varieties; Menziesi (or Atomaria), 4-8 in., white or pale blue, speckled black, with several varieties; macu-lata, 6 in., white, with a violet-purple blotch on each corolla lobe; and phacelioides, pale blue, with a white centre.