FLOWER ADVERTISEMENTS 271 



(p. 253). Miiller showed that in the Alps, butterflies 

 play a more important part in this connection than 

 in the plains. 



Flower Advertisements. 



Flowers may be said to be the most ancient of 

 advertisers. Those which are pollinated by insect 

 agency specially lay themselves out to attract insects. 

 Their advertisements are of two main types : colour 

 and scent. As a rule, in the Alps both exist together ; 

 in other cases colour alone is relied on, and the 

 flowers are scentless. But many plants go even a 

 stage further : they provide ''free samples" of honey 

 or pollen for some or all of the insects whose com- 

 pound eyes they have managed to attract by their 

 advertisements. 



Conspicuousness may be more or less confined to 

 the flowers themselves, or other parts of the plant 

 may share in it. We have already seen (p. 124) 

 how diff'erent parts of the flower may be specialised 

 as the conspicuous organs. We have also discussed, 

 in the case of the Gentians (p. 58), the evolution 

 of the coloured pigments of flowers. Frequently one 

 or more organs or sets of organs are greatly enlarged, 

 and highly coloured, and are thus rendered more 

 conspicuous. A good example of this may be found 

 in a comparison of the corollas of the Field Pansy 

 (p. 161) or Long-spurred Violet (p. 128) with that of 

 the Two-flowered Violet (p. 253). Or, again, con- 

 spicuousness may be increased by the massing of a 



