210 



ENTOMOLOGY 



(Figs. 263, 89) to hold the pollen, do not occur on other than pollen- 

 gathering species of insects. Caudell found that out of 200 species of 

 Hymenoptera only 23 species had branched hairs and that these species 

 belonged without exception to the pollen-gathering group Anthophila, 

 no representative of which was found without such hairs. Similar 

 branched hairs occur also on the flower-frequenting Bombyliidae and 

 Syrphidae. 



The most extensive modifications in relation to flowers are found in 



CO 



3 



FIG. 264. Adaptive modifications of the legs of the worker honey bee. A , outer aspect of 

 left hind leg; B, portion of left middle leg; C, inner aspect of tibio-tarsal region of left hind 

 leg; D, tibio-tarsal region of left fore leg; a, antenna comb; an, auricle; b, brush; c, coxa; 

 co, corbiculum; /, femur; p, pecten; pc, pollen combs; s, spur; sp, spines; ss, spines; t, 

 trochanter; //, tibia; v, velum; w, so-called wax pincers; 1-5, tarsal segments; /, metatarsus, 

 or planta. 



Pronuba, as already described, and above all in Apidse, especially the 

 honey bee. 



Honey Bee. The thorax and abdomen and the bases of the legs 

 are clothed with flexible branching hairs (Fig. 263), which entangle 

 pollen grains. These are combed out of the gathering hairs by means 

 of special pollen combs (Fig. 264, C, pc) on the inner surface of the planta 

 of the hind tarsus, the middle legs also assisting in this operation. From 

 these combs, the pollen is transferred to the pollen baskets, or corbicula 

 (Fig. 264, A, co), of the outer surface of each hind tibia, the pollen from 



