xx LIST OF ILLUSTRATIONS 



I'AGK 



27. Section of sarsaparilla stem 42 



28. Section of sycamore stem .43 



29. Section of clematis stem ...... 46 



30. Section of date-palm stem ... . . . 47 



31. Section of pillwort stem . 48 



32. Section of marestail stem 49 



33. Section of club-moss stem . . . . . . 50 



34. Section of rush stem 51 



35. Section of ivy stem .52 



36. Section of Brazilian liana stem . . . . 54 



37. Section of mid-rib of rhododendron leaf . . . 55 



38. Section of pine leaf .... 56 



39. Section of blade of laurel leaf .'.... 60 



40. Section of mid-rib of laurel leaf .. ... . 61 



41. Section of blade of sunflower leaf . . . , . 62 



42. Section of mid-rib of sunflower leaf .... 63 



43. The growing-point of a stem 65 



44. Section of blade of deadly nightshade leaf ... 66 



45. Section of stonecrop leaf 67 



46. Section of pine leaf . , 69 



47. Section of blade of water-lily leaf ...... 70 



48. Section of blade of Indian corn leaf . . . . 71 



49. Transparent leaves of a moss ..... 73 



50. Section of the base of a Virginian creeper's leaf stalk . 77 



51. Breathing pores or "stomata" of monkey-puzzle leaf . 79 



52. " Stomata " of tulip leaf . . . . . 81 



53. Central portion of male begonia flower .... 85 



54. Central portion of female begonia flower ... 86 



55. Stamens from various flowers . . . . . 88 



56. The tubular corolla of foxglove opened ... 90 



57. Pollen grains falling from stamens of mallow . . 92 



58. Spiny pollen grains of hollyhock 93 



59. Ripe stamens of mallow flower 94 



60. Section of anther of a lily -95 



61. Compound pollen grains . . . . . . 96 



62. Sections of pollen grains 98 



63. Stigma of evening primrose with pollen tubes . . 100 



