122 GENERAL BIOLOGY 



pound eyes of a worker and of a drone bee; in what respects 

 do they differ? What explanation can you give for this 

 difference? The eyes of the queen are like those of the 

 workers. Three ocelli are present as in the grasshopper. 

 Observe the position and the structure of the antennae. 



3. Mouth Parts. The mouth parts of the bee are the same 

 in number as those of the grasshopper, but greatly modified 

 and adapted to different functions. 



(a) Labrum. This is a flap of skin forming an upper lip. 

 (6) Mandible. There is a pair of mandibles or jaws be- 

 hind the labrum. Both the mandible and the labrum 

 are quite similar to those of the grasshopper, but 

 somewhat reduced in size. The mandibles of the 

 worker differ slightly from those of the queen and the 

 drone. 



The remaining mouth parts, the maxillae and labium, 

 are much modified and together form a proboscis for 

 sucking liquid food. 



(c) Maxilla. The palp of the maxilla is reduced in size to 



a mere rudiment. The remainder of the appendage 

 forms the hollow outer portion of the proboscis. 



(d) Labium. Of this appendage there are three chief 



parts, the base, the labial palps, and the glossa or 

 " tongue. " The glossa forms the center of the pro- 

 boscis, is covered with long hairs, and ends in a spoon- 

 like lobe called the labellum. 



To study the mouth parts straighten them out, 

 away from the head, cut off the entire tip of the head 

 and mount this on a slide in glycerin. It may be 

 necessary to separate these parts somewhat with 

 needles. 

 Make a drawing of the mouth parts. 



