THE GRASSHOPPER 21 



How are the antennae joined to the head? What kind of 

 joint between the segments ? 



Above the antennae near the large eyes look for small eyes 

 or ocelli. Look closely for a third ocellus. Note the cover- 

 ing of the head. Do you find lines of division ? When these 

 lines are deep and extend from one line to another they 

 mark divisions between plates. Do you find plates on the 

 face and sides of the head ? How many ? The one between 

 the eyes is called the epicranium. Follow it backward and 

 forward until you have traced its shape. 



Below the epicranium is a bandlike plate, the clypeus, 

 and below this is the movable labrum, or upper lip. Trace 

 each of these and find the irregularities of surface. 



Below each of the large plates is a plate called gena, or 

 cheek. Trace these, noting shape and surface. Do the 

 plates now traced cover the entire surface? 



Make a drawing of the face showing all the parts 

 named (Xs)- 



(2) Lift the labrum to see the freedom of motion. Does 

 the living animal move the labrum up or outward ? Observe 

 a live grasshopper eating to determine this. 



(3) With the scissors or scalpel sever the labrum from 

 the clypeus and remove it. Lay it carefully on a piece of 

 paper outside up. 



This exposes two hard, dark colored mandibles meet- 

 ing in the center. Note their method of coming together. 

 Of what use are they? Observe a living specimen to find 

 the direction of their motion. Grasp one firmly with the 

 tweezers and with a quick outward pull remove it. Remove 

 the other in the same way and lay both in proper order 

 below the labrum. 



