THE FLOWER AND THE BEE 



earned), and 5 or 6 red-flowered primroses are pollinated by 

 butterflies. Many lepidopterid flowers occur among the 

 orchids, and in the genus Habenaria the beautiful, purple- 

 fringed orchis is a butterfly-flower (Fig. 64), while the greenish 

 or white species are pollinated by crepuscular or nocturnal 

 moths. In some instances I have found the grayish hairs of 

 moths adhering to glutinous surfaces. 



Butterflies do not confine their visits to butterfly-flowers 

 alone, but may visit any flower. They experience, however, 

 more or less difficulty in sucking nectar on flat surfaces and 

 consequently prefer tubular flowers with concealed nectar 

 the longer the tongue the more marked this preference becomes. 

 They also occasionally fly to pollen-flowers and search them for 

 sweet secretions. But no flowers are so frequently visited by 

 butterflies as social flowers of the type of the Composites, to 

 which 40 to CO per cent of their visits are made, or 3 to 6 times 

 as many visits as are made to butterfly or bee flowers. Every 

 one has observed a cloud of butterflies hovering over a clump 

 of purple thistle-heads, or the yellow flowers of the elecampane 

 (Inula Helenium), or the dull-white clusters of the thorough- 

 wort. The male butterflies, which are often pleasantly scented, 

 pursue the females from flower to flower without any regular 

 order. 



Butterflies often rob flowers of their nectar without render- 

 ing any service in return. Both honey-bees and butterflies 

 steal thousands of pounds of alfalfa nectar annually through a 

 crevice in the side of the flower. Many other leguminous 

 flowers are robbed in the same way, but in many species the 

 petals close up so firmly that access to the nectar can be gained 

 only in the normal way. While butterflies cannot pollinate 

 the flowers of the blue flag (Iris versicolor), they often stand 

 on the upper or under side and, inserting their tongues side- 



132 



