THE COLOURS OF FLOWERS. 



are bell-shaped, and each contains a pistil and five 

 stamens, like any other perfect flower. But the outer 

 florets are generally sterile ; and instead of being 



FIG. 17. Flower of corn bluebottle (Cenia-urea cyanus); highest type of cynaroid 

 composite ; bright blue. 



bell-shaped they are split down one side and unrolled, 

 so as to form a long ray ; while their corolla is at 

 the same time much larger than that of the central 



