COLOR IN FLOWERING PLANTS. 87 



dustrions of flower-guests, because they provide not only for 

 their own needs, but also for those of their numerous progeny. 

 Many of them are wise systematists, as Aristotle noted long ago, 

 who wrote, " A bee on any one expedition does not pass from one 

 kind of plant to another, but confines itself to a single species and 

 does not change until it has first returned to the hive." Color 

 must help them much ; but since they visit a great variety of 

 flowers, it is seemingly most useful as a means of distinguishing 

 intermixed species, one color, in itself, being perhaps little more 

 attractive than another. 



Kerner, Kronfield, Forbes, and Delia Torre have seen bumble- 

 bees fly for hours from one flower to another of the same kind, 

 ignoring other species which grew mixed with them. To such per- 

 sistent and intelligent industry our field and meadow flowers, at 

 least in part, owe their endless variety of shape and color, and as 

 long as bees live there will be fresh modifications for us to won- 

 der at. The " soft sun-brush " directed by the exquisite taste of 

 these little connoisseurs of true art is continually producing new 

 chefs-d'c&itvre. 



Nor is the work of flies to be despised. Some of them are 

 almost as enterprising and have apparently as keen a sense of 

 beauty as many bees and butterflies. Muller speaks of the largest 

 and most handsome of the saxifrages as the " masterpiece of the 

 Syrphidce," (the most highly developed of flies). Fly-flowers have 

 often dark-red color and nectar so scanty that it does not pay the 

 bees to take it — e. g., bryophyllum. In New Zealand flies largely 

 take the place of bees, which are there exceedingly scarce. Some 

 species are exclusively dependent on them. Lurid, snaking spots 

 or markings or disgusting odors often tell the secret of fly-attrac- 

 tion (arum, Dutchman's pipe, skunk-cabbage, smilax). 



But some flowers, neither showy nor fragrant, are yet abun- 

 dantly visited both by bees and flies (bryonia, bur-cucumber, 

 etc.). Kunth found that the greenish petals of some of these 

 plants affect a photographic plate as strongly as those of white, 

 violet, or blue flowers. It is not at all unthinkable that the won- 

 derful eyes of insects may be sensitive to colors invisible to our 

 coarser sense. Kunth adds that the glands of these plants may 

 perhaps contain ethereal oils noticeable to insects though imper- 

 ceptible to man. 



Surely, in the face of all these facts, it can not be denied that 

 there is some relation between the conspicuousness or fragrance 

 of flowers and their pollinization and pollinizers, especially since 

 it is possible in the various insect groups to trace a connection 

 between the two, and since, in the absence of animals of one kind, 

 others have sometimes been delegated to do the work, the botan- 

 ical character of the region changing correspondingly ; as, for 



