The eggs, caterpillars, pupæ, cocoons, and adult of some moth or similar stages of a butterfly. _Definitions._ _Prolegs_, short, unsegmented appendages found in the larva. _Caterpillar_, the larva of a moth or butterfly. _Spiracles_, openings into the trachæ or breathing tubes. _Tubercles_, knob-like projections. _Chrysalis_, the pupa stage of a butterfly. _Cocoons_, the covering spun by the larva before changing to the pupa. _Observations._ 1. State the color and appearance of the larva. If tubercles or spines are present, state where. Where are the spiracles? How do you distinguish the head, thorax, and abdomen in the case of the caterpillar? 2. What kind of mouth parts has the caterpillar? 3. How many prolegs has the caterpillar? Of what use are they? How does the number of prolegs differ from that of the caterpillar in the case of the grub? maggot? currant worm? 4. What is the advantage of the cocoon? What is its color, appearance, and material? Is it composed of a tough substance, or is it easily torn? Where are cocoons found out of doors? Where would you look for chrysalids? (Explain differences in locations.) Describe the cocoons of tussock moth, clothes moth, leaf roller. 5. What is the difference between a Cecropia cocoon which contains a living pupa and one that has been parasitized? What is the appearance of a parasitized caterpillar? 6. What rudimentary structures can you identify in the pupa? What kind of mouth parts has this stage? 7. Which of these stages is the active stage? Which stage is quiescent? What is really going on in the quiescent stage? In which stage does the insect grow? feed? If the insect were harmful, in which stage would it do the damage? How? 8. Describe what occurs when the pupa changes into the adult. What is the appearance of the wings in the beginning? What changes take place? 9. What kind of mouth parts has the adult? Describe. 10. Describe the antennæ. How do the antennæ of moths and butterflies vary? 11. What is the size and appearance of the eggs? Are they laid singly or in groups? _Suggested drawings._ a. A caterpillar, side view. b. A pupa, ventral view. c. An adult, dorsal view. d. A few eggs. 5. Development of the Chick _Materials._ An incubator, a brooder, a setting of eggs. _Directions._ Read carefully the directions for setting up and regulating the incubator. Remember that the temperature should average 103 degrees and should not vary more than two or three degrees above or below this. Candle the eggs from time to time and note difference in appearance, as development proceeds, especially as to transparency and size of the air space. An egg that is transparent after ten days is probably infertile and should be removed. Eggs which are developing properly will show from this time on a well developed air space, and will be quite opaque. The veins often give a spider-web appearance.