462 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1920. 



only simple eyes, which seem to be direct heirlooms from the eyes 

 of worms. The compound eyes (figs. 1 to 4) are paired and lie on 

 the sides and top of the head, while the simple eyes (fig. 4, only one 



Figs. 1 to 4.— The three castes of honeybee, enlarged. Fig. 1, worker; fig. 2, queen; 

 fig. 3, drone; and fig. 4, head and mouth parts of worker. 



shown), usually three in number and arranged in a triangle, lie near 

 the top of the head between the compound ones. 



