CLASSIFIED LIST OF ILLUSTRATIONS XXV11 



PAGE 



77. Diagram. Gridiron system of arranging drains. Fig. 84 254 



78. Diagram. System of arranging drains. Fig. 85 255 



79. Diagram. System of arranging drains. Fig. 86 255 



80. Diagram. Natural system of arranging drains. Fig. 87 256 



81. Diagram. Sectional view of ditching machine. Fig. 90 259 



82. Diagram. Relation of root-hairs to soil particles. Fig. 99. ... 287 



83. Diagram. Effect of deep and shallow tillage on roots. Fig. 100. 294 



84. Diagram. Effect of alkali salts on plant cells. Fig. 103 312 



85. Diagram. Nematodes entering a root. Fig. 108 392 



86. Diagram. Types of soil bacteria. Fig. 109 395 



87. Diagram. Influence of surface slope on sunshine received. 



Fig. 125 458 



88. Curves. Relative size of textural groups. Fig. 20 74 



89. Curves. Average analysis of common classes of soil. Fig. 24 . 78 



90. Curves. Relation of texture to crop adapation. Fig. 25 79 



91. Curves. Relation of texture to water capacity. Fig. 44 145 



92. Curves. Distribution of water in columns of soil. Fig. 46. ... 148 



93. Curves. Relation of texture to capillary water capacity. Fig. 47. 150 



94. Curves. Relation of structure to water capacity. Fig. 48 ... . 152 



95. Curves. Water capacity of sandy soil in field. Fig. 49 156 



96. Curves. Water capacity of clay soil in field. Fig. 50 157 



97. Curves. Water capacity of silt soil in field. Fig. 51 157 



98. Curves. Relation of capillary rise to texture. Fig. 54 175 



99. Curves. Relation of capillary rise to texture. Fig. 55 177 



100. Curves. Relation of capillary rise to texture. Fig. 56 179 



101. Curves. Relation of capillary rise to texture. Fig. 57 179 



102. Curves. Lateral capillary movement. Fig. 58 184 



103. Curves. Annual precipitation and percolation, England. Fig. 61. 193 



104. Curves. Relation of evaporation to mulch formation. Fig. 64 . 204 



105. Curves. Relation of soil moisture to yield of dry matter. Effect 



of weeds. Fig. 66 209 



106. Curves. Influence of cloth tent on soil moisture. Fig. 68 ... . 215 



107. Curves. Relation of soil condition to the formation of nitrates. 



Fig. 112 414 



108. Curves. Daily range of soil temperature. Fig. 122 454 



109. Curves. Mean annual range of air and soil temperature. Ne- 



braska. Fig. 123 455 



110. Curves. Effect of color on soil temperature. Fig. 124 457 



111. Moldboard plow with shares. Fig. 34 Ill 



112. Middlebreaker plow. Fig. 75 236 



113. Hillside plow. Fig. 118 441 



114. Plow with parts named. Fig. 127 466 



115. Heel-plate of plow. Fig. 128 467 



116. Sulky moldboard plow. Fig. 129 468 



