HYMENOPTERABEES 



145 



related to this. I shall therefore, in the following account, substantially repeat 

 the descriptions of this distinguished investigator. 



A. Membrane-winged Insects (Hymenoptera). 



Of insects concerned with the pollination of European flowers, these are the 

 most important. The first place must be given to 



Bees (Apidae), 

 which of all insects stand on the highest level of specialization in regard to flower 

 pollination, and are alone capable of putting into action numerous flower-mechanisms 

 which remain closed to all other visitors. Not only are they most skilful in the 

 quest for flower-food, but they are also most zealous, for besides feeding upon 

 substances derived from flowers as adults, they rear their young entirely on such 

 food. The whole existence of bees is therefore, says Hermann Miiller (* Fertilisation,' 

 p. 46), bound up with flowers to such an extent that they by themselves present 

 more adaptations to procuring flower-food, and considerably more with regard to 

 pollination, than all other orders of insects, with the possible exception of Lepidoptera, 

 put together, and have therefore brought about a larger number of floral adaptations. 

 The honey-bee (Fig. 58, 5, 6) is pre-eminent among its kind as regards adapta- 

 tion to pollination. With wonderful certainty it solves the problems presented 







Fig. 58. Pollen-collecting apparatus on the hind-legs of bees (after Hermann Miiller). (i) Right 

 liind-Ieg of Macropis labiata Ps. 9, seen from behind and within. (2) The same laden with pollen of 

 Lysimachia vulgaris. (3^ Right hind-leg of Bombus Scrimshiranus K. 5, seen from behind and within. 

 (4) Tibia (shin) of the same, seen from the outer side (collecting-basket). (5) Right hind-leg of the honey- 

 bee (Apis mellifica L. ), seen from behind and within. (6) Tibia (shin) of the same from the outer side, 

 f, coxa (hip) ; ir, trochanter; yj femur (thigh) ; il, tibia (shin) ; /, tarsus (foot) ; /', basal joint of the tarsus. 

 F'g- () naturally only shows in side view the collecting-hairs of Macropis, which cover the outer surfaces 

 of the tibia, and basal joint of the tarsus. 



by the most involved floral mechanisms. It goes to work in a purposeful manner, 

 as if conscious of the end in view, and confines its attention strictly to the species 

 of flower it has selected. Its body presents the most perfect adaptations to the 

 collection of pollen and the sucking of nectar. For gathering pollen it has a 

 pollen-collecting apparatus on its hind-legs, and this is the most perfect arrangement 

 of the kind in any of the ' scopulipedes,' one of the chief divisions of the bees. 



