210 THE MOLECULAR ARCHITECTURE OF PLANT CELL WALLS 



Phase difference, 68 



relation to path difference, 69 

 Phycomyces sporangiophore, 187 et seq., 

 199 



chitin orientation in growth zone, 180, 

 189 



elastic properties of wall, 189 et seq. 



growth, 187 



growth zone and staining reactions, 

 192 

 Picea tracheids, 133, 135 



variation of major extinction postion, 

 161, 162 

 Picken, 198 

 Pinus, 118, 119 

 Pits, see cell wall, 

 Pleochroism, 69 

 Polarised light, nature of, 52 et seq. 



propagation through crystals, 53, 57 



propagation through fibre, 59 et seq. 

 Polygalacturonic acid, 25, 26 

 Polyuronides, 25 

 Preston, 118, 119, 203-206 

 Priestley, 193 



see Tupper-Carey and Priestley 

 Primary wall, see Cell Wall 

 Protococcus, 92 

 Protoplasm, fibrillar hypothesis, 8 



granular hypothesis, 8 



reticular hypothesis, 8 



tensile strength, 8 



viscosity, 8 

 Protoplasmic structure and growth, 198 



et seq. 

 Pseudotsuga, birefringence in outer layer 



of tracheids, 164 

 Purkinje, 6 



Quercus alba, 19, 119 

 Quercus borealis, 119 



Ramie, see Fibres 

 Ramsay, 150 

 Ranby, 89, 90, 206 

 Reed and Rudall, 89, 205 

 Refractive indices, definition, 51 



and molecular structure, 52, 53 



interpretation, 55, 56 



measurement, 54 



of fibres, 53, 57 

 and index ellipsoid, 57 et seq. 



of mixtures, 56 



relation to path difference, 61 



Wiener effect, 56 

 Resolving power, 86 



of electron microscope, 87 

 Roelofsen, 191, 192 



see Oort and Roelofsen 

 Rotation diagram, 40 et seq. 



layer lines in, 41, 44 



Rudall, 198, 206 

 see Reed and Rudall 



Sanio, 6, 7 



Sassafras officinale, 143 

 Schmidt, 198, 206 

 Schultze, 8 

 Schwartz, 8 

 Schwendener, 8 

 Selligue, 5 

 Sieve tubes, 143 

 Singh, 118, 137, 166, 204 

 Solan um lycopersicum, 147 

 Spirogyra, 92 

 Spongomorpha, 187 

 Sponsler, 43 

 Starch grains, 65 

 Steenberg, 115 

 Staudinger, 74, 79, 90 

 Staudinger and Mohr, 79 

 Strasburger, 7, 8 

 Stuart model of cellulose, 46 

 Sutcliffe, see Brown and Sutcliffe 

 Svedberg, 81 

 see Gralen and Svedberg 



Tensile strength of materials, 82 

 Tracheids, 14, 17, 113 et seq., 140, 142 



birefringence, 133 

 of outer layer, 163, 164 



crossed fibrillar structure, 128 



development, 154 et seq. 



diagram of structure, 136 



dimensional relationships, 152 



layering in, 113, 114 et seq. 



major extinction position, 116, 118, 

 119 



rate of differentiation, 142 



removal of one cell wall, 116 



striations, 119, 160 



variation of spiral angle, 158 et seq. 



X-ray diagram, 120 

 Tradescantia staminal hairs, 148 

 Tupper-Carey and Priestley, 193 



Unit cell, 33, 42 

 dimensions in native cellulose, 43, 44 

 mercerised cellulose, 110 

 Unger, 6 



Valonia, 88, 89, 90, 92 et seq., 117, 142, 

 185, 196 

 lamellation, 96 

 major extinction position, 95 

 structural model, 98 et seq. 

 uniplanar orientation, 96 

 watch-glass cells, 93 

 X-ray diagram, 94 



