LIST OF ILLUSTRATIONS. 



FIGURE PAGE 



Showy Tick-Trefoil (Des medium 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 100 



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 12 1 



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



28. Flowers of bur-reed 129 



29. Flowers of hazel 131 



30 and 31. Jb lowers 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> 3 8 > 39 4. ar >d 4*. 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 



