4. How can you tell the head end? Tell how the amount of work that the mouth and mouth parts do affects their size and indirectly that of the region where they are. 5. What senses and sense organs has the maggot? Test any of these senses or organs gently, by any means at your disposal, or recall any experience you have had along this line. Which senses or organs seem to be best developed? 6. Explain briefly how the active or sluggish habits either determine or are determined by the condition of the senses or sense organs. 7. Since "Mother Nature" seems to want maggots to develop rapidly, tell how she economizes in energy and material when forming them. 8. Show how the development of maggots in refuse matter is actually beneficial. 9. From the standpoint of flies and human welfare, show why maggots should not be allowed to live,--stating how they may be prevented. 10. Look up the story of the pupa of the house fly; the development and work of the botfly; of the ox-warble; of the tsetse fly. _Suggested drawing._ a. The maggot or grub, side view, × 4. THE LIVING COCKROACH _Materials._ Individual specimens in cages, jars, or wide-mouth vials with cotton stoppers to admit air. Several roaches in large cages with material for food and concealment. _Observations._ 1. What is the general color and the average size of cockroaches? 2. During what time of the day are roaches most active? Where do they hide at other times? How do their shape and color aid concealment? Note any odd or striking colors or marks which might make them distinguishable to their mates. 3. Is the roach a quick or a slow moving animal? How does it get about,--by running, jumping, walking, crawling, swimming, or flying? Turn your specimen on its back and see how it recovers its proper position. Notice the relative size and development of the wings and their use in flying. 4. If uninjured, your specimen has six legs. Why don't they step on each other? Notice the stiff hairs on the legs and the white pads under the feet. How would these structures be useful to the animal? 5. The large, black, shiny eyes are on the front and sides of the head; the long "horns," or feelers, are attached just below the eyes. Upon which sense, sight or feeling, do you think the roach depends more? Explain your statement. 6. Beside the mouth are a long and a short pair of "feelers"; perhaps these are for tasting or smelling. What do roaches like to eat? Do they choose their food? What damage do they do? 7. How can a house be rid of cockroaches? _Suggested drawing._ a. A cockroach, seen from above. THE LIVING SPIDER _Materials._ Living spiders, preferably large ones, in cages; individual specimens in battery jars or wide-mouth bottles. Cocoons. Simple lenses. _Observations._ Each pupil may feel sure that if treated fairly any of the common spiders may be handled without fear of bite or injury.