Seed Dispersal--Lesson 164 Detailed Study of Seed Dispersal--class-room lesson 165 Seed collections; man as a disperser of seeds 166 The Sugar Maple--field exercises 168 Maple Leaves--class-room lesson; correlations 169 Weed Studies 170 Observation lesson on weed seeds 171 Grasshopper--field exercises; class-room lesson 172 Aphides 174 Tomato Worm--the adult; the chrysalis 175 The Crow; correlations 177 CHAPTER X. FORM III: WINTER Care of Plants in the Home 178 Plant Cuttings 179 Selection of cuttings; potting of rooted cuttings 179 Evergreens--class-room lesson 181 Collection of Wood Specimens 182 Related Reading 183 How Animals Prepare for Winter 183 Summary of Lessons; correlations 184 Chickens 185 Conversation lesson; arithmetic lesson; care and food of chickens 185 Physical Science Phase of Nature Study 188 Solids, Liquids, and Gases 188 Change of State 189 Expansion of Solids 189 Practical applications; questions for further investigation 190 Expansion of Liquids--applications 192 The Thermometer 193 Expansion of Air 194 Sources of Heat and Light 194 Notes for a Series of Lessons 194 Conduction--problems 196 Convection--problems, convection in gases; applications 198 Radiation of Heat--problems 199 CHAPTER XI. FORM III: SPRING Window Boxes 201 Window Gardens 201 Suitable Plants; Fertilizer 202 Soil Studies--constituents 203