White flowers often develop red or blue coloration. It is interesting to note that the red and white varieties of the hyacinth were derived from the wild blue form earlier than the yellow. Darwin gives an instance of a white and red rose produced on the same root, also of white and pink flowers on a single plant of _Antirrhinum majus_. _Cratægus oxyacantha_, a dark pink hawthorn, has been known to throw out a tuft of pure white blossoms. Every stage of the transition from white to red is placed before us by the rose family. The thorns are white, rarely tinged with rose; in the pear and apple the flowers are white, regularly shaded with red; and one of the _Spiræas_ is rose, rarely white, while in the roses proper the six species are rose-colored, but the prairie rose changes to white. Under cultivation the wild geranium has been seen to produce upon the same plant both white and blue flowers. Good examples of the transition from white to blue and from blue to white may be met with in the _Ranunculaceæ_ and _Leguminosæ_. _Delphinium tricorne_ is bright blue, sometimes white, _Viola canadensis_ has the petals white inside but the upper ones tinged with violet beneath, _Astragalus_ has a part of the species white and a part purple, while it is common to find blue and white varieties of _Hepatica_ growing on the same grassy bank. White flowers pass more readily into red, blue, or yellow than any one of these colors can be converted into any other, since it is easier to develop a new pigment than to transform one already existing. This is confirmed by the experience of florists, who always seek to obtain a white variety from which to develop the desired hue.