■WHY PERFECT FLOWERS NEED TO ATTRACT INSECTS. 23 



the orifice, and then expanded into a flat border. At the very bottom of it is a 

 short and thick mass, consisting of a broad stigma, to the outside of which three 

 sets of anthers grow fast : these face away from the stigma, so that none of the 

 pollen can fall on it ; and the crooked tube of the flower, with a narrow opening, 

 must effectually prevent the wind from giving any aid. What can this mean ? 



43. To explain the puzzle which such flowers present, we have to consider that, 

 by their bright colors, or odors, or the nectar they offer, — sometimes by all three 

 allurements combined, always by the latter, — they attract insects ; by whose 

 usually rough or bristly heads, or legs, or bodies, pollen may be brushed out of 

 the anthers, or caught as it falls, and some of it carried to or dropped upon the 

 stigma. And we must infer that these blossoms are so constructed and arranged 

 on purpose that insects may visit and fertilize them ; and that many species are 

 absolutely dependent upon such assistance : for, as they would not set seed, they 

 could not permanently exist, except for the insects which they nourish in return 

 for such service. So we conclude that honey is the wages paid to insects in 

 return for the work they do ; and that the fragrance of flowers and their beautiful 

 colors, as well as their honeyed sweets, are not merely for our delight, and for the 

 use of the insects they feed, but are of primary use to the plant itself. 



44. In confirmation of this view, it is found that flowers which are fertilized by 

 the wind, of which there are numerous sorts, produce neither bright-colored 

 corollas, nor fragrance, nor honey. 



45. Now that we know the way of it, nothing is more interesting than to 

 notice how particular flowers, each in its own way, are arranged so as to be helped 

 by the insects that visit them. Iris-flowers (Fig. 12), for instance, are visited by 

 bees. These alight upon the outer and recurving, usually crested or bearded di- 

 visions of the flower, down the base of which is the only access to the nectar below. 

 When sucking out the nectar with its proboscis, the bee's head is brought down 

 beneath the anther ; when raised, it will rub against it and brush out some of the 

 pollen : this, loosely adhering to its hairy surface, is ready to be deposited upon 

 the shelf of stigma above, not when the bee leaves the flower, but when it repeats 

 the action. When Arethusa (Figs. 13-15) is visited, the head of the bee enters 

 the mouth of the flower : in raising it to leave the flower after extracting the nec- 

 tar, the head hits the front edge of the helmet-shaped anther, raises it like a lid, 

 and receives one or more of the soft pellets of pollen that fall upon it : on again 

 entering the flower and again rising to depart, the pollen-loaded head is first 



