List of Illustrations xiii 



PAGE 



Fig. 54. Developmental cycle of plastids in cells of Stellaria 



media 193 



Fig. 55. Eegion of maturation of excised tomato root 195 



Fig. 56. Manometer for measuring root pressure 196 



Fig. 57. Manometer assembly, detail 197 



Fig. 58. A battery of manometers with attached pressure 



equipment 198 



Fig. 59. Titration of distribution of aucuba-mosaic virus in 



a tomato root 201 



Fig. 60. Tyrosinase distribution in an excised tomato root 205 



Fig. 61. Hyperhydric enlargement of cells of seed primordia 



of Antirrhinum 206 



Fig. 62. Meristematic cells in Nicotiana callus culture 207 



Fig. 63. Scalariform cells in Nicotiana callus culture _ 208 



Fig. 64. In vitro grafts of cambium cultures 213 



Fig. 65. Cross section of a Nicotiana callus culture 214 



Fig. 66. Detail from figure 65 215 



Fig. 67. Disorganized vascular tissue from a sunflower tumor 



tissue culture 216 



Fig. 68. Formation of stem growing point on a Nicotiana 



callus culture 223 



Fig. 69. Section showing Nicotiana callus cultivated in a rab- 

 bit 's eye 224 



Fig. 70. Detail from figure 69 225 



Fig. 71. Effect of aeration on differentiation of a Nicotiana 



callus culture 226 



