The Life Processes of the Individual 135 



is concave on the posterior surface to fit the rounded thorax. 

 The three ocelli (0) in the worker are arranged in a triangle 

 at the top of the head, the antennae (Ant) arise from the 

 center of the face. On the posterior surface is the foramen 

 magnum (For) through which pass nerves, 

 oesophagus, dorsal blood vessel and tra- 

 cheal tubes connecting the head and 

 thorax. Below the foramen magnum is 

 the fossa (PrbFs) where the proboscis 

 is attached. 



The heads of the queen and the drone 

 differ from that of the worker in size and 

 shape (Fig. 69, A, B and C). The face 

 of the queen (B) is more nearly round 

 and is relatively wider. That of the 

 drone (C) is larger and nearly circular, 

 this being due to the unusual develop- 

 ment of the compound eyes (E) which 

 meet at the vertex of the head, crowd- 

 ing the ocelli (0) to the front near the 

 bases of the antennae. The head of the 

 queen is smaller than that of the worker. 



The mandibles (Fig. 68, A, Md) or 

 jaws, which are of special interest to the 

 beekeeper, are situated on the sides of 

 the mouth anterior to the base of the 

 proboscis, being attached to the clypeus 

 (Clp) and the postgena (Pge) by two 

 articulations, so constructed that they 

 serve only to crush or bite food and 

 not to grind it. The mandibles of in- 

 sects, when present, work sidewise and 

 not up and down in a median plane, as do our jaws. The 

 mandibles of the three types of bees differ in shape and size. 

 Those of the worker (Fig. 70, A) are hollowed out and have 

 smooth and rounded edges, while those of the drone (Fig. 70, 

 B) and of the queen (Fig. 69, B) are pointed and notched. 



FIG. 69. Anterior 

 view of heads of 

 worker (A), queen 

 (B) and drone (C), 

 with front, anten- 

 nae and proboscis 

 removed from each. 



