xiv List of Illustrations 



FIG. PAGE 



17. Some common fresh-water algae; (a) zygnema; (b) mon- 



geotia; (<) spirogyra (much magnified) 95 



1 8. Pine-sap (Monotrapa hypopitys] 99 



19. Starch grains of the potato (a) and of wheat (b) 104 



20. Epidermal cell and one stoma of a fern (much magnified) 107 



21. Stoma of a cycas (much magnified) 108 



22. Four natives of South Africa : i. A South African 



groundsel; 2, a typical cactus; 3, a sponge; 4, a 

 milkweed in 



23. A climbing spray of the pea 114 



24. Parallel-veined leaves of the Indian shot 122 



25. Net-veined leaves of the lime tree 124 



26. Blade-like leaves of the Iris with clasping bases 125 



27. Crosswise section of a Palmetto trunk 127 



28. Crosswise section of the trunk of a young oak tree 



showing growth rings 135 



29. Wild roses 137 



30. A lily-flower 140 



31. Seed-vessel of the tulip 140 



32. Sweet-flag (Acorus Calamus) 141 



33. A single floret of the sweet-flag (magnified) 144 



34. June aspect of the cat-tail flags 145 



35. Single florets of the cat-tail flag (magnified) 147 



36. Some familiar grasses 1 50 



37. " Marram grass," " beach grass " or " sea-sand " reed 



(Ammophila arundinacea of Gray} 152 



38. Stems of the rye, showing the knots or nodes 158 



39. Ligula of millet-grass 161 



40. Oats and yarrow with analyses of their flowers 163 



41. Single flower of a grass (magnified) 167 



42. Caryopsis of the wheat (magnified) 168 



43. Sand-bur grass (Cenchrus tribuloides] 170 



44. Squirrel-tail grass (Hordeum jubatuni} 171 



45. Common reed (Phragmites communis) 174 



46. Five familiar water-rushes 178 



47. A wood-rush (Lazula campestris) 180 



48. Lengthwise section of the tubular leaf of a "knotty- 



leaved " rush (magnified). 182 



49. Flower-cluster and flower analysis of a common water- 



rush {Juncus articulatus] 184 



