230 TEOPICAL NATURE, AND OTHER ESSAYS. 



preserved, and then formed the starting-point of a whole 

 series of further variations, resulting in those marvellous 

 adaptations for insect fertilization, which have given 

 much of their variety, elegance, and beauty, to the floral 

 world. For details of these adaptations we must refer 

 the reader to the works of Darwin, Lubbock, Herman 

 Miiller, and others. We have here only to deal with 

 the part played by colour, and by those floral structures 

 in which colour is most displayed. 



Attractive Odours in Flowers. — The sweet odours of 

 flowers, like their colours, seem often to have been 

 developed as an attraction or guide to insect fertilizers, 

 and the two phenomena are often complementary to 

 each other. Thus, many inconspicuous flowers — like the 

 mignonette and the sweet-violet, can be distinguished 

 by their odours before they attract the eye, and this 

 may often prevent their being passed unnoticed ; while 

 very showy flowers, and especially those with varie- 

 gated or spotted petals, are seldom sweet. White, or 

 very pale flowers, on the other hand, are often exces- 

 sively sweet, as exemplified by the jasmine and clematis ; 

 and many of these are only scented at night, as is 

 strikingly the case with the night- smelling stock, our 

 butterfly orchids {Hahenaria chlorantha), the greenish- 

 yellow Daphne pontica, and many others. These white 

 flowers are mostly fertilized by night-flying moths ; and 

 those which reserve their odours for the evening pro- 

 bably escape the visits of diurnal insects, which would 

 consume their nectar without effecting fertilization. The 

 absence of odour in showy flowers, and its preponderance 

 among those that are white, may be shown to be a fact 

 by an examination of the lists in Mr. Mongredien's work 



