INTRODUCTORY CHAPTER 



Those flowers which are dependent upon night-flying in- 

 sects for their pollen, contrive to make themselves noticeable 

 by wearing white or pale yellow, red, blue, and pink being with 

 difficulty detected in the darkness. They, too, frequently in- 

 dicate their presence by exhaling perfume, which in many 

 cases increases in intensity as the night falls, and a clue to 

 their whereabouts becomes momentarily more necessary. This 

 fact partially accounts for the large proportion of fragrant 

 white flowers. Darwin found that the proportion of sweet- 

 scented white flowers to sweet-scented red ones was 14.6 per 

 cent, of white to 8.2 of red. 



We notice also that some of these night-fertilized flowers 

 close during the day, thus insuring themselves against the visits 

 of insects which might rob them of their nectar or pollen, and 

 yet be unfitted by the shape of their bodies to accomplish their 

 fertilization. On the other hand, many blossoms which are 

 dependent upon the sun-loving bees close at night, securing the 

 same advantage. 



Then there are flowers which close in the shade, others at 

 the approach of a storm, thus protecting their pollen and nectar 

 from the dissolving rain ; others at the same time every day. 

 Linnaeus invented a famous " flower-clock," which indicated 

 the hours of the day by the closing of different flowers. This 

 habit of closing has been called the " sleep of flowers." 



There is one far from pleasing class of flowers which entices 

 insect-visitors, not by attractive colors and alluring fragrance 

 but " by deceiving flies through their resemblance to putrid 

 meat imitating the lurid appearance as well as the noisome 

 smell of carrion."* Our common carrion flower, which covers 

 the thickets so profusely in early summer that Thoreau com- 

 plained that every bush and copse near the river emitted an 

 odor which led one to imagine that all the dead dogs in the 

 neighborhood had drifted to its shore, is probably an example 

 of this class, without lurid color, but certainly with a suf- 

 ficiently noisome smell ! Yet this foul odor seems to answer 

 the plant's purpose as well as their delicious aroma does that of 



* Grant Allen. 

 5 



