LIST OF ILLUSTRATIONS. 



FIGURE PAGE 



Showy Tick-Trefoil (Desmodium Canadense) 



Frontispiece. 



1. A thin slice from a leaf, seen under the microscope . 36 



2. Finger-veined leaves 41 



3. Feather-veined leaves 42 



4 and 5. Types of lobed and divided leaves ... 43 



6. Parallel- veined leaves 45 



7, 8, and 9. Roots of carrot, frogbit, and radish . . 56 



10. Sundew . .64 



11. An Australian pitcher plant 67 



12. Insect-eating pitchers of the Malayan nepenthes . 69 



13. Male and female flower of a sedge .... 74 



14. Beginnings of sex in a pond weed .... 75 



15. Flower, with petals removed, showing stamens and 



pistil 77 



16. Grains of pollen sending out pollen-tubes . . 81 



17. Flower of a shrubbery plant, Weigelia . . .82 



1 8. Pin-eyed primrose 100 



19. Thrum-eyed primrose loo 



20. Male and female flowers of arrowhead . . . 108 



21. Flower of water-plantain 109 



22. Flower of orchid 117 



23. Pollen-masses of orchid 118 



24. The two pollen-masses, very much enlarged . .119 



25. The common arum, or cuckoo-pint .... 120 



26. Spike of the cuckoo-pint 121 



27. Male and female flower of salad -burnet . . .127 



28. Flowers of bur-reed ....... 129 



29. Flowers of hazel 131 



30 and 31. Flowers of wheat 134 



32. Clusters of flowers 138 



33 and 34. Florets from the centre of a daisy . . .140 



35. Floret from the ray of a daisy 141 



36. Flower-head of a thistle 144 



37 33, 39, 40, and 41. Forms of fruits .... 151 



42, 43, 44, and 45. Floating fruits 153 



46, 47, and 48. Adhesive fruits 157 



49. First steps in the evolution of the stem . . . 163 



