158 
Beekeeping 
The muscles for moving the legs are located inside the 
joints and are inserted on the chitinous walls. 
The last tarsal joint on each leg carries a pair of bilobed 
claws (Fig. 82, Cla), which differ among the three types of 
bees. Those of the drone are bent more nearly at right 
angles than those in the workers and queens and those of 
the queen are larger than the claws of the workers. Between 
the claws is a lobe (empodium, Emp) used when the bee 
walks on a smooth surface. On such a surface the claws 
are useless and the sticky empodium is lowered and flat¬ 
tened, providing a good foothold. 
The motion of the legs in walking is typical of all insects. 
The legs move in two sets; the fore and hind legs on one 
side move in the same direction as the middle leg on the 
opposite side, thus giving a triangle for support at all times. 
In flight the legs hang freely and are forced somewhat 
backward, except when they are being used as in the manipu¬ 
lation of pollen (p. 123). 
PROTECTIVE APPARATUS 
Worker bees defend the colony by means of the sting, 
situated usually in a cavity at the tip of the abdomen (Fig. 
76) but capable of marvelously rapid action when it is 
protruded. As was stated earlier (p. 140), this sting cavity 
is formed by the infolding of the eighth, ninth and tenth 
segments of the abdomen. The sting is homologous with 
the ovipositor of other insects (see Snodgrass, l.c. pp. 76- 
77) and is made up of parts considered by some embry¬ 
ologists as comparable with the legs and mouth parts of 
the more anterior segments of the bee. The sting of the 
worker bee is straight while that of the queen is longer, 
curved and less strongly barbed. 
The sting (Fig. 83) and its accessory apparatus form a 
rather complex structure. The shaft consists of three parts, 
a dorsal sheath (ShS) along which move two barbed lancets 
(Let). The sheath is enlarged at the anterior end into a 
