INSECT POLLINATION 315 



declare, in effect: " Honey of the finest quality given 

 away here." No indication is given of the necessity 

 of a quid pro quo, and the eager visitors pressing their 

 way to the refectory are altogether unconscious of the 

 fact that they are made to carry a precious vitalizing 

 burden to the next flowers that lure them to their 

 service. 



In brief, it is mainly in quest of food that insects visit 

 flowers, and of the triune of attractions, colour, scent, 

 and food, the last-named is chief. The food offered by 

 flowers to their guests is essentially honey, or nectar, 

 and pollen. The honey bait is laid by the great maj ority 

 of entomophilous flowers. I suppose most of us remem- 

 ber the days of our youth when we gathered the easily 

 removed corollas of the White Deadnettle (Lamium 

 album), and sucked them for honey; we also bear in 

 mind that the sweetness came from the lower end of the 

 corolla tube. There, indeed, is the nectary in which the 

 honey is secreted. The nectary is a special gland for 

 honey secretion; it is situated variously in different 

 flowers, sometimes on stamens, very frequently in close 

 relation to the pistil, sometimes on the corolla. Remov- 

 ing a petal from the flower of a Buttercup and examining 

 it carefully, we detect a rounded scale, which forms a 

 kind of pocket at the base ; this is the nectary. In the 

 umbelliferous plants the nectary is found on the ovary, 

 and in the Violet it is formed from two of the stamens. 

 The Honeysuckle secretes a large quantity of honey, 

 frequently half filling its long corolla tube. The flower 

 does not open until evening, when it can be visited by 

 long-tongued Hawk-Moths. Only moths with very long 

 tongues can explore the full length of the tube, but when 



