THE FLOWER 125 



243. The object of the insects' visits is usually a 

 sweetish liquid, the nectar secreted by glands commonly 

 in the forms of swellings of the tissue of the receptacle 

 at the base of the flower. These are the nectaries. In 

 flowers with spurred petals, like the Columbine, the nectar 

 is secreted at the end of the spur, whence it can be sucked 

 up only by the long-tongued insects, which are the most 

 effective in transferring the pollen of these plants. 



244. In addition to nectar, the pollen itself, a highly 

 nutritious product, is sought by many insects. 



245. Protection of the nectar. Such a desirable food 

 as the nectar is sure to be attractive to insects which, by 

 reason of their size or habits, are not likely to make any 

 return of service to the plant. Ants, for instance, travel 

 all over the herbage in the vicinity of their nests in search 

 of food. Happening upon the wells of honey within the 

 flower, they would drink their fill, and perhaps bring their 

 fellow-ants to the place, as their custom is, with the result 

 that the flower would be drained of its nectar; but these 

 visitors would be too small, in the case of many flowers, 

 to brush the pollen from the tall stalked stamens, or de- 

 posit it on the stigma at the summit of the lengthened style. 

 And, further, even were it possible for transference to be 

 made by the adherence of the pollen to the bodies of the ants, 

 the slow movements of these insects, their short-sightedness 

 and blind wanderings, and their indiscriminate visiting of 

 all sorts of plants would make them unprofitable carriers, 

 as regards any one vegetable species, when compared with 

 swift-flying, long-sighted, and often times discriminating 

 insects like the various bees, butterflies, and moths. 



246. Consequently, very many flowers are fortified 

 against the invasions of the ants and other undesirable 

 visitors. One of the common and effective methods of 

 defense is a coating of downward-pointing, or in cases 

 stioky, hairs on the flower stalk or on the calyx. In 

 some instances the secretion from the hairs not only pre- 

 vents insects from going farther up the stalk, but holds 

 any trespasser firmly, so causing its death. 



