168 CAPRIFOLIACE^E [CH. 



exactly the right position for it to be rubbed off when 

 another flower in the physiologically female condition is 

 visited. 



Fig. 45. Horse-chestnut, ^Esculus Hippocastanum. A, a j flower in 

 the physiologically ? condition ; B, the same, cut longitudinally, in the 

 <? condition. C, a g flower in section (E and P). 



The Guelder Rose (Fig. 141) offers a curious case. 

 The outermost flowers of the inflorescence have their 

 corollas much larger than those within the margin ; this 

 enlargement is at the expense of the essential organs, 

 for the flowers are quite barren, and serves to advertise 

 the inflorescence as by white flags. 



In the Honeysuckle (Fig. 142) the long tube of the 

 corolla is not only an efficient shelter for the abundant 

 honey, but keeps it so far back from the orifice that only 

 long-tongued insects such as moths can reach it con- 

 veniently. These are attracted by the increased scent 

 and honey at night. They find the long style projecting 

 straight forwards, about 25 mm. beyond the throat of the 

 corolla; the stamens similarly project about 15 mm. Both 

 the pollen-laden anthers and the stigma are slightly up- 

 turned, so that the moth touches first the stigma and 

 then the anthers with its abdomen as it poises to suck. 



Examples of long-tubed flowers adapted for Lepi- 

 doptera are 



Lonicera Caprifolium L. Periclymenum. 



