84 THE AMERICAN HOTANIST. 



of the flowers white on the first evenini;- the\- open, but b3^ 

 the second evening they have become yellow. The plant 

 is pollinated by hawk-moths and the change in color, it is 

 believed, may guide them in their work. On the first 

 evening the antlers are ripe and stand directly in front of 

 the entrance, while the stigma is bent downward. In this 

 manner self-fertilization is averted. 



In Cohasa scandens the flower on expanding is green 

 but soon assumes a violet hue ; in the Christmas rose 

 ( Hellehorus niger) the sepals change from white to green ; 

 while itt aome flowers of the mustard family (Carclamine) 

 the petals change from green to yellow. Many red flowers, 

 I have noticed, fade nearly to white before the petals fall, 

 as in some roses, spiraeas and the flowering almond. I 

 once transplanted some poppies before the}' had blossomed . 

 Those undisturbed produced flowers with scarlet centers 

 and white margins, while the plants that had been moved 

 displayed only pure white flowers. A plant oi Nemophila 

 insignis in my garden throughout the summer yielded a 

 profusion of blossoms with deciduous blue petals, but in 

 September the petals became persistent changing from 

 blue to green and increasing in size. 



But in no family is this peculiarity of floral coloration 

 so marked as in the Boraginacese, or borage family. The 

 flowers of borage in bud and when first expanded are pink 

 but change to blue. They are very attactive to bees, and 

 during the past summer I watched the honeybee and 

 bumblebees for the purpose of ascertaining whether they 

 found the red or blue blossoms the more attractive. They 

 were repeatedly seen to visit flowers of both colors, but 

 no preference was observable in their behavior. In Mvo- 

 sotis arvensjs, which also belongs to this family, the 

 corolla has in bud a yellow tube with pink lobes, which 

 change to blue and fade to white. M. versicolor is yellow 

 changing to blue or violet; while M. alpestris produces 

 dark blue, bright blue, reddish and even snow white 

 flowers. Echinospermum lappula is white in the bud, red 

 before expanding, and finally bright blue. The corolla of 



