CHAPTER XIII 



Color in Nature. Colors of flowers and the inter-relation 

 of flowers cmd insects. Colors of animals and their physico- 

 chemical causes. The theories of protective coloration, warn- 

 ing and alluring colors, mimicry and recognition marks. 



But few American naturalists have entered the broad and 

 fascinating field of Nature's colors. The subject was one 

 of intense interest to Darwin and his co-workers, Wallace, 

 Bates and Fritz Miiller, and has been largely developed by 

 the recent Darwinians in Germany and England. A few 

 Americans however have made valuable contributions to the 

 subject which we shall consider in this chapter. 



What is the cause and what the function of the bewilder- 

 ing array of colors which we find on every hand? Are they 

 useful to their possessors, and hence preserved through se- 

 lection, or are they simply an expression of a reckless gener- 

 osity of Nature, who lavishes her gifts with wild prodigality 

 upon her creatures, regardless of whether they are bene- 

 fited thereby or no? In the case of chlorophyl, the green 

 coloring matter of leaves, and haemoglobin to which the red 

 color of the blood is due, we know of course the physiolog- 

 ical value, but most colors (those of flowers and insects for 

 example) are of uncertain value, although many very pretty 

 theories have been invented to account for them. 



The colors of flowers are formed as by-products of their 

 metabolism. Their function is possibly to attract insects and 

 thus aid in their fertilization. We have all of us been fa- 

 miliar since childhood with the ' ' busy little bee, ' ' and how it' 

 "employs each shining hour" has ever been set before us for 

 our edification and emulation; but the beautiful manner in 

 which Nature has fashioned her children, both bee and flower, 

 for the accomplishment of her "purpose" is not so familiar 

 to us all. To attempt to recount here even in small measure 

 the life of the bee would carry us too far aside from our 

 main theme, and would moreover be a thankless task for one 

 following in the footsteps of a Maeterlinck or a Fabre. We 

 may however pause for a moment to consider the relation 

 between a single sort of bee and a single kind of flower, in 

 order to gain some notion of the wonderful co-adaptation 



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