INSECT -POLLINATED FLOWERS 8i 



pollinated flowers have no nectaries, denotes that the nectaries 

 serve to entice insects. 



The insects which visit flowers in order to obtain honey or 

 pollen, belong to the families of the Beetles, Flies, Bees (in- 

 cluding Wasps and Humble-bees), and Butterflies (with Moths). 

 The majority of Flies and Beetles have very short tongues, and 

 are not intelligent, so that they can only obtain such honey as 

 is easily accessible ; the hover-flies form an exception to this 

 rule, for they possess long tongues. The Bee-family provides 

 the most important pollinating insect-agents ; the simplest 

 members have only short tongues ; but many species of bees 

 and wasps are clever, and possess long tongues, consequently 

 they are able to discover and obtain honey which is carefully 

 concealed and deeply placed. Finally, many Butterflies and 

 Moths, with tongues even longer than those of humble-bees, 

 can reach honey which is so deeply placed at the bottom of 

 long tubes as to be inaccessible to the latter insects. 



We find that flowers of different shapes and tints do not 

 receive equal attention from all these families of insects. 

 Flowers like those of the Parsley-family, with freely-exposed 

 honey (fig. 183), or the Buttercup, with honey scarcely con- 

 cealed (fig. 61), receive relatively more visits from the short- 

 tongued insects — flies and beetles — than do flowers with 

 deeply-concealed honey {e.g. Geranium, fig. 165). Opposed 

 to these flowers which are suited to the requirements of many 

 kinds of insect-visitors are others which are specially adapted 

 to receive certain particular classes of insects. The flowers of 

 the Pea, Vetch, Clover, and Violet have their honey so well 

 concealed that only clever insects with tolerably long tongues 

 can reach the nectaries (figs. 96, 158); they are pollinated 

 by the agency of bees, and are specially adapted to receive 

 their visits, and may therefore be termed " Bee-flowers." The 

 Monkshood (fig. 151) and Foxglove (fig. 193) are similarly 

 "Humble-bee flowers" (see pages 120, 157). Finally, 

 Pinks and the Honeysuckle are adapted to receive Butterflies 

 and Moths respectively : their honey is not fully accessible to 

 bees. 



Comparing the actinomorphic flowers of the Buttercup with 

 the zygomorphic " Bee-flowers " mentioned, it will be noted 

 that the buttercup-flower may be entered from any side, and 

 the visiting insect may crawl about in the flower and receive 



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