THE GRASSHOPPER. 49 



3. The sounds (stridulatiori) made by some individuals 

 (males) while on the wing. 



4. Its hours of activity. 



5. Its natural enemies. 



6. The effect of temperature upon its activity. Go out 

 some frosty morning for this purpose. 



Place a live specimen under a tumbler, and study : 



1. Its respiratory movements. Observe the opening 

 and closing of two lips that guard the entrance to a large 

 spiracle just above the base of one of the middle legs. 

 Find other active spiracles. 



2. The size and arrangement of its legs in relation to 

 the locomotor habits of the animal; which legs are most 

 serviceable in walking, in leaping. 



3. Its manner of feeding. Place some fresh leaves of 

 clover or of lettuce under the tumbler with the insect, 

 and watch it eat. If kept without food for half a day, it 

 will eat greedily. 



Liberate an active specimen in a warm room, and 

 measure its longest leap in number of times its own 

 length. 



External Anatomy. Observe the relative development 

 of head, thorax, and abdomen. 



Examine, as before, the upper parts of the head, eyes, 

 ocelli, and antennae. 



I. Mouth Parts. Study the mouth parts with especial 

 care ; for in the grasshopper all the typical mouth parts 

 of an insect are present and well developed. Find, pro- 

 ceeding from the front : 



1. A large, two-lobed labrum. 



2. A pair of toothed, horny mandibles, covered by the 

 labrum. 



3. A pair of maxilla, jointed, compound organs, each 

 bearing at its summit three appendages. 



NEED. ZOOL. 4 



