CONTENTS 



I. The Composition and Purposes of Plants 



PAGE 



§ 1. The plant is composed of living matter .... 1 



§ 2. The purposes of plants 3 



§ 3. Great difierences among plants 3 



§ 4. The oaks, maples, elms, ferns, mosses, and pond-scums are 



not all of the same kind among themselves ... 4 



§ 5. A species 6 



§ 6. Scope of -work described 7 



n. The Material of which Plants are made up 



§ 7. The plant is an engine 9 



§ 8. Water, charcoal, and ash 10 



§ 9. Leaves shrink in drying 12 



§ 10. Mineral coatings 13 



§ 11. Uses of mineral coatings 13 



§ 12. Aquatic plants with mineral coatings .... 1-1 



§ 13. Water cultures, with and without mineral salts . . 15 

 § 14. Ash or mineral salts in the water of streams . . .15 



§ 15. Elements found in plants 16 



§ 16. Substances serving as food 18 



§ 17. Compounds in the plant 18 



§ 18. Tests for the contents of plants 19 



TTT . The Manner in which Different Kinds of Work 

 are divided among the Members of tue Body 



§ 19. Kinds of work, or functions of the plant .... 21 



§20. Organs 22 



