VIU 



Page 



Thread formation in the potato ( I-ilositas) i6i 



Diaphysis (Growiuff out) of the potato 163 



Formation of tubers witliout foliage 164 



Aerial potato tubers 165 



Premature ripening of fruits 165 



Rusty plums 166 



l-'urther |)henomena of premature ripening 166 



Mealiness of fruit 166 



Bitter pit in the apple 168 



Stoniness of pears and lithiasis 170 



X'arieties of fruit suitable for dry soils 1.74 



Stunting of plants 175 



Pilosis 177 



Lignification of roots 179 



Ball dryness of the Ericaceae 181 



Means of overcoming lack of moisture in the soil 182 



Irrigation 182 



Cultivation of the soil 183 



Mulching of the soil 184 



Soils with a plant cover 185 



l'"orest litter 186 



Forests 187 



Fallow land 188 



b. Loamy soils 189 



General characteristics 189 



Covering of the soil with silt 191 



Improvement of soils which are becoming compact 194 



Inundations 195 



Conversion of lands into swamps 196 



Burning of plants in moist soils 199 



r)cla_\ cd seeding 200 



Souring of seed 20i 



Souring of potted plants 203 



Injudicious watering 206 



Use of saucers under pots 208 



Running out of potatoes 208 



Sensitiveness of the sweet cherry 200 



Tan disease 209 



Girdling of the red beech 219 



Root disease of the true chestnut (Mai nero) 219 



Rootblight of sugar and fodder beets. 220 



Tropical plants 227 



Root-rot of sugar cane 227 



' ' "Diseases of cotton 228 



Castor bean cultures 229 



Tobacco 229 



CofTec 230 



Cocoa and tea 231 



Other tropical plants 231 



Means for overcomiug the disadvantages of heavy soils 232 



' Harrowing 236 



Use of lime, marl, and plaster 22,'j 



3. Disadvantages of moor soil 240 



Acids in the soil 240 



Raw humus 241 



Meadow ore 243 



Poisoning of the soil by metallic sulfur 250 



Susceptibility to frost of moor vegetation 251 



The usefulness of the spruce 253 



Changes in moor soil through cultivation 256 



Rotten bark 258 



Horticultural moor plants 260 



Specking of orchids 261 



Chapter HI. Unfavorable chemical soil constitution 264 



I. Relation of the food stuffs to the soil structure 264 



A. Soil absorption resulting from chemico-physical processes 264 



B. Work of the soil organisms 268 



