236 THE STllUCTURE OF FLOWERS 



its use as a fertilising agent ; for, according to Mr. Darwin, " if 

 wasps were to become extinct in any district, so would Epipactis 

 latifolia. " 



Honey, I need scarcely say, is the principal object of attraction 

 to bees, butterflies, moths, and many other insects which assist in 

 the work of fertilisation. It is secreted by specialised organs 

 known as nectar glands. " In the flower," according to Dr. 

 Goodale, an eminent American botanist, " these glands consist 

 usually of specialised parenchyma, not unlike the secreting 

 surface of the stigma." " Nectar glands," continues the author, 

 " may occur in any part of the flower, upon its bracts, or upon 

 some part of the flower-stalk near it. From the nectar glands of 

 ])roper floral organs the secretion of nectar is generally copious, 

 and is prone to collect in minute cavities, such as shallow pits, or 

 in conspicuous special receptacles, the so-called nectaries. The 

 period of most copious secretion of nectar usually coincides with 

 the maturity of the anthers or of the stigma." Here we perceive 

 another of Nature's beautiful contrivances for carrying out her 

 purposes. Just at the time when the pollen is ready to do its 

 work of fertilisation, or the stigma to receive it, a copious supply 

 of honey both attracts and rewards the insect pollen-carriers. 



The odours of flowers must be classed amongst the most 

 potent attractions of insects. White flowers are more generally 

 fragrant than those of any other colour. As examples of the 

 accuracy of this proposition, I would refer to those delicately- 

 scented flowers, the Lily of the Valley, the Jasmine, and the Butter- 

 fly orchis. I cannot do better tlian (|uote the words of Mr. 

 Darwin in explanation of this : — " The fact of a large proportion 

 of white flowers smelling sweetly may depend in part on those 

 which are fertilised by moths requiring the double aid of conspicu- 

 ousness in the dark, and of odour. So great is the economy of 

 Nature that most flowers which are fertilised by crepuscular or 

 nocturnal insects emit their odour chiefly or exclusively in the 

 evening." 



I have ventured to call attention to a comparatively large 

 number of important facts, and for the purpose of giving my 

 authorities have quoted largely. If these quotations have the 

 effect, as I trust they may, of directing attention to, and inducing 



