Directions are given for preparing and mounting objects, implying that the reader will collect specimens for himself, which is to be strongly recommended as the best method of acquiring a practical and useful acquaintance with the objects. These will serve to furnish permanent landmarks in the great ocean of structural forms, will probably recall in after-years pleasant recollections of early excursions in search of the beauties of nature, and, surely, deepen the conviction of the existence of their All-wise Creator. J. W. G. CONTENTS. CHAP. PAGE I. THE MICROSCOPE 1 II. THE MOUNTING OF OBJECTS 10 III. VEGETABLE ELEMENTS AND TISSUES 19 IV. VEGETABLE ORGANS 31 V. FERNS 49 VI. MOSSES 54 VII. ALGÆ 64 VIII. LICHENS 91 IX. FUNGI 96 X. ANIMAL ELEMENTS AND TISSUES 113 XI. ARTICULATA 127 XII. RADIATA 153 XIII. PROTOZOA 155 XIV. OPTICAL PRINCIPLES 167 PLATE I. [FRONTISPIECE.] VEGETABLE TISSUES, &c. Fig. 1. Leaf of Geranium: cells, chlorophyll, and intercellular passages. 2. Cells of Apple. 3. Starch-granules: _a_, of Wheat; _b_, of Arrowroot; _c_, of Potato; _d_, of Oat; _e_, of Lentil; _f_, of Rice. 4. Cells of Potato, containing Starch. 5. Garden Rhubarb-stalk: _a_, raphides; _b_, reticulated duct; _c_, spiral vessel; _d_, woody fibre; _e_, annular vessel. 6. Wood-cells from stem of Chrysanthemum. 7. Deal, transverse section: _a_, glandular tissue; _b_, woody fibre. 8. Deal, longitudinal (radial) section of glandular tissue. 9. Deal, longitudinal section of woody fibre. 10. Deal, tangential section. 11. Holly, wood of: _a_, porous cells; _b_, _d_, _e_, wood-cells; _c_, dotted ducts. 12. Hairs, vegetable: _a_, _b_, of Groundsel; _c_, of London Pride; _d_, _e_, of Geranium; _f_, of Chrysanthemum. 13. Epidermis of Geranium-leaf. 14. Style of Crocus, with pollen-granule and-tube. 15. Pollen-grain of Crocus, with pollen-tube. 16. Pollen of Primrose. 17. Pollen of Sunflower. 18. Pollen of _Convolvulus major_. 19. Caraway-seed. 20. Needle-point. 21. Sting of Nettle. 22. Hair of Spiderwort. 23. Hair of Spiderwort, single cell. 24. Epidermis of Geranium-petal. 25. Petal of Chickweed. 26. Sepal of Chickweed. 27. Seed of Poppy. 28. Epidermis of _Deutzia_. 29. Seed of Mignonette. 30. Pollen of Chickweed, dry. 31. Pollen of Chickweed, in water. 32. Flower of Chickweed. 33. Epidermis of petal of Chickweed. 34. Hairs of calyx of Chickweed. 35. Hairs of seed of _Collomia_. 36. Stem of Dicotyledon, section of.