Preface 



in order that it might set fertile seed, and Linnaeus had to come 

 to his rescue with conclusive evidence to convince a doubting 

 world that he was right. Sprengel made the next step forward, 

 but his writings lay neglected over seventy years because he ad- 

 vanced the then incredible and only partially true statement that a 

 flower is fertilized by insects which carry its pollen from its an- 

 thers to its stigma. In spite of his discoveries that the hairs within 

 the wild geranium protect its nectar from rain for the insect bene- 

 factor's benefit ; that most flowers which secrete nectar have what 

 he termed " honey guides " — spots of bright color, heavy veining, 

 or some such pathfinder for the visitor on the petals ; that some- 

 times the male flowers, the staminate ones, are separated from the 

 seed-bearing or pistillate ones on distinct plants, he left it to Darwin 

 to show that cross-fertilization by insects, the transfer of pollen 

 from one blossom to another — not from anthers to stigma of the 

 same flower — is the great end to which so much marvellous floral 

 mechanism is adapted. The wind is a wasteful, uncertain pollen 

 distributor. Insects transfer it more economically, especially the 

 more highly organized and industrious ones. In a few instances 

 humming birds, as well, unwittingly do the flower's bidding while 

 they feast now here, now there. In spite of Sprengel's most pa- 

 tient and scientific research, that shed great light on the theory of 

 natural selection a half century before Darwin advanced it, he 

 never knew that flowers are nearly always sterile to pollen of an- 

 other species when carried to them on the bodies of insect visitors, 

 or that cross-pollenized blossoms defeat the self-pollinated ones in 

 the struggle for survival. These f^icts Darwin proved in endl-ess 

 experiments. 



Because bees depend absolutely upon flowers, not only for 

 their own food but for that of future generations for whom they 

 labor ; because they are the most diligent of all visitors, and are 

 rarely diverted from one species of flower to another while on 

 their rounds collecting, as they must, both nectar and pollen, it fol- 

 lows they are the most important fertilizing agents. It is estimated 

 that, should they perish, more than half the flowers in the world 

 would be exterminated with them ! Australian farmers imported 

 clover from Europe, and although they had luxuriant fields of it, 

 no seed was set for next year's planting, because they had failed to 

 import the bumblebee. After his arrival, their loss was speedily 

 made good. 



Ages before men cultivated gardens, they had tiny helpers 

 they knew not of. Gardeners win all the glory of producing a 

 Lawson pink or a new chrysanthemum ; but only for a few seasons 

 do they select, hybridize, according to their own rules of taste. 

 They take up the work where insects left it off after countless cen- 

 turies of toil. Thus it is to the night-flying moth, long of tongue, 

 keen of scent, that we are indebted for the deep, white, fragrant 

 Easter lily, for example, and not to the florist ; albeit the moth is in 



vii 



