The workers, as might be surmised by the importance and variety of their functions, are structurally very peculiar Their tongues (Fig. 20, _a_), labial palpi (Fig. 20, _b, b_), and maxillæ (Fig. 20, _c, c_), are very much elongated, while the former is very hairy, and doubles under the throat when not in use. The length of the ligula enables them to reach into flowers with long tubes, and by aid of the hairs they lap up the nectar. When the tongue is big with its adhering load of sweet, it is doubled back, enclosed by the labial palpi and maxillæ, and then extended, thus losing its load of nectar, which at the same time is sucked into the large honey-stomach. The bees, at will, can force the honey back from the honey-stomach, when it is stored in the honey-cells or given to the other bees. [Illustration: Fig. 21. _a_--Jaw of drone. _b_--Jaw of queen. _c_--Jaw of worker. ] The jaws (Fig. 21, _c_) are very strong, without the rudimentary tooth, while the cutting edge is semi-conical, so that when the jaws are closed they form an imperfect cone. Thus these are well formed to cut comb, knead wax, and perform their various functions. Their eyes (Fig. 5) are like those of the queen, while their wings, like those of the drones, attain the end of the body. These organs (Fig. 3), as in all insects with rapid flight, are slim and strong, and, by their more or less rapid vibrations, give the variety of tone which characterizes their hum. Thus we have the rapid movements and high pitch of anger, and the slow motion and mellow note of content and joy. [Illustration: Fig. 22. _Part of Posterior Leg of Worker, outside, much magnified._ _t_--Tibia. _b_--Rim of hairs. _p_--Pollen basket. _t s_--Joint of tarsi, _c_--Claws. ] On the outside of the posterior tibia and basal tarsus is a cavity, made more deep by its rim of hairs, known as the pollen basket (Fig. 22, _p_). In these pollen baskets is compacted the pollen, which is gathered by the mouth organs, and carried back by the four anterior legs. Opposite the pollen baskets are regular rows of golden hairs (Fig. 23, _e_), which probably aid in storing and compacting the pollen balls. On the anterior legs of the workers, between the femur and tibia, is a curious notch (Fig. 24, _C_), covered by a spur (Fig. 24, _B_). For several years this has caused speculation among my students, and has attracted the attention of observing apiarists. Some have supposed that it aided bees in reaching deeper down into tubular flowers, others that it was used in scraping off pollen, and still others that it enabled bees to hold on when clustering. The first two functions may belong to this, though other honey and pollen-gathering bees do not possess it. The latter function is performed by the claws at the end of the tarsi. [Illustration: Fig. 23. _Part of Worker's Posterior Leg, inside, much magnified._ _e_--Rows of hairs. _t_--Tibia. _c_--Claws. ] [Illustration: Fig. 24.