POLLINATION 73 



These will show how widely the pollination arrangements differ 

 in complexity and in precision. The insects that are mainly 

 responsible for the pollination of flowers visit them in search of 

 either pollen or nectar, which they collect or feed upon. The 

 most important visitors are bees, butterflies and moths, and flies, 

 though beetles and other insects may also be of use. Of these 

 the short-tongued flies are the least intelligent, and are also unable 

 to reach deeply seated nectar. The long probosces of some of the 

 flies, of the bees and of the moths and butterflies, enables them to 

 feed on many flowers which exclude the shorter-tongued insects. 

 Of all these insects the bees are the most intelligent and methodical 

 visitors, and many of the most beautifully adapted flowers are 

 bee-flowers. The study of the entrance to a beehive is a most 

 instructive one, and it is often possible to form an opinion as to 

 the flowers visited from the variously coloured masses of pollen 

 carried in on the legs of the workers. The behaviour of bees and 

 other insect visitors should be watched when they are visiting 

 particular flowers and the insects caught, and the structure of their 

 mouth-parts examined. Some particulars will be found in the 

 portions of this work which deal with insects. 



Without attempting any consistent classification, flowers 

 may be grouped according to the presence or absence of nectar 

 and the protection and concealment of the honey. Some flowers, 

 such as the Poppy (Vol. IV. p. 21) and the Rose (Vol. IV. p. 52), 

 offer only pollen to their visitors. These have as a rule little 

 specialised methods of pollination. The simplest flowers with 

 nectar have this freely exposed, so that it can be obtained by any 

 insect visitor. The Cow-Parsnip (Vol. IV. p. i) is a good example 

 of such a flower. In other flowers the nectar is partly concealed, 

 but still usually accessible to short-tongued insects. The Butter- 

 cup (Vol. III. p. 99, Fig. 53) and the Wild Strawberry (Vol. III. 

 p. 168) are examples of this. More specialised flowers have the 

 nectar concealed and often accessible only to long-tongued insects. 

 Most of the more beautiful arrangements for pollination de- 

 scribed above are in flowers of this class. These flowers may be 

 regular, and approached indifferently from any side, as in the 

 Periwinkle or the Red Campion ; but more usually in the highly 

 specialised forms they are irregular, as in the Dead-Nettie or the 



