224 HYMEXOPTERA. 



with the thorax by the abdominal ring (r^), which is 

 in the form of a slender peduncle. The basal portion 

 is hollowed out so that the convex, posterior part of 

 the thorax can fit into it. Now it will at once be seen 

 that this peculiar connection enables the insect to 

 raise its abdomen and bring it downward and for- 

 ward with considerable force. The abdomen also pos- 

 sesses great pliability as well as the power of driving 

 the blow of a thrusting instrument, like a sting. The 

 development of the sting, and the necessity for its 

 effectual action, probably explains the small, wasp-like 

 waists of many Hymenopterous insects. 



The compound eyes (Fig. 177, n'; Fig. 176) are 

 hairy, and in the workers, widely separated ; the 

 three ocelli (Fig. 177, oc') are prominent. Accord- 

 ing to Lubbock's observations bees possess a keen 

 sense of vision, being often much affected by light, as 

 shown by a bee following a lighted lamp down cellar, 

 " flying round and round like a moth." Their power 

 of distinguishing colors is apparently excellent, and 

 this capacity, together with the bee's acute sense of 

 smell, has probably exerted a determining influence 

 upon the color and fragrance of flowers. It is well 

 known that insects carry pollen on their bodies from 

 one flower to another, and in this way effect the plant's 

 healthy fertilization. That there should be this mutual 

 dependence existing between plant and insect, notably 

 between plant and bee, is a matter of very great inter- 

 est, and no one can read the observations of Henslow,^ 



1 Origin of Eloral Structures, International Scientific Series, 

 Appletpn & Co., New York, 1888. 



