Examine a preparation of the compound eye with the low power or as demonstrated with the stereopticon. What is the shape of an eye element of the compound eye? About how many eye elements are there in a compound eye? _Feeding._ 11. Do grasshoppers eat and drink while in captivity? Put a fresh bunch of grass which has been sprinkled with water in a vivarium with grasshoppers that have had no food or drink for twenty-four hours and watch results. 12. What is the position of the grasshoppers in feeding? In what direction do the jaws move in feeding? Compare this with the direction of movement of your own jaws. What is the use of the palps? What do you think is the use of the "molasses" or saliva that flows from the mouth? _Respiration._ 13. Describe the breathing movements of a grasshopper and explain the relation of the movements to inhalation and exhalation of air. 14. Find the exact location and number of spiracles on the abdomen. There are two pairs of spiracles on the thorax. Find them. How do the spiracles prevent the entrance of dust? Describe a trachea as seen in a mounted preparation with the aid of a microscope or stereopticon. _Protection._ 15. Explain how the colors of the grasshopper may be protective or useful when at rest in its natural habitat and when in flight. 16. Does the shell cover the entire body? What are the advantages of such a covering? A shell is likely to hinder activity, sensitiveness, and growth. How are such disadvantages overcome in this case? 17. What senses are probably most relied upon to detect approaching danger? Give evidence to support your answer. 18. What is the position of the hind legs when at rest? What relation has this to safety? _Reproduction and Development._ 19. Describe the ovipositors and the probable method of their use. Describe the egg packets of grasshoppers, if discovered. About how many eggs in one? (They are sometimes seen against the glass sides of the vivaria.) 20. If you have young grasshoppers of various ages, arrange a set of them in what seems to you to be the order of their development. How do young grasshoppers differ from adults? What changes take place as they develop? What kind of metamorphosis is this? Summary of Important Points in the Study of the Grasshopper 1. How many and what distinct regions of the body are there? 2. How many antennæ? Compare their length with that of the body. What other sense organs did you discover? 3. How many legs? For what specially adapted? How? 4. How many wings? What is their resting position? How do the fore wings differ from the hind wings? How do the hind wings fold? 5. To what kind of feeding are they adapted, biting or sucking the food? How many and what sets of mouth parts are there? 6. How is air necessary for respiration obtained? 7. In what various ways are grasshoppers fitted for life in meadows and weed plots? 8. How do they meet winter conditions?