Index — 224— Hoagland 



Selenium, essentiality for plant, 44 



Selenium, toxicity for ajiimal, 44 



Silicon, essentiality of, 29 



Sodium, absorption by plant. 111, 167 



Sodium colloid in soil, 14; plate 3 



Soil acidity, 15, 16 



Soil alkalinity, 16; plates 4-5 



Soil solution, composition, 5, 7-9 



Soil solution, displacement method, 6-7; plate 2 



effects of cropping on, 8-11 



experiments, technique of, 6-12; plates 1, 2 



pressure membrane apparatus, 7 



seasonal relations, 8 



Sugar in roots, 128 



Sulphate ions, soil solution, 12 



Supplying power of soil, 9, 10; plate 1 



Temperature of roots, 117, 118; plate 26 



Tomato, yields in artificial culture and soil, 115; plate 20 



Toxic substances in soil, 5 



Translocation salts, concentration in transpiration stream, 101 



effect of transpiration, 73, 82, 94, 96, 100, 101 



— ■ — • and growth, 97 



nature of, 90-92 



_ _ path, 73, 92-95, 98 



relation to water absorption, 72-83 



use of ra.dioactive isotopes, 88, 94-96, 99 



Transpiration and salt absorption, 72-83 



Transpiration and salt movement, 72-83, 94, 96, 100, 101 



Valonia CELLS, SAP composition, 50-53 

 Variability of cultures, 19 

 Vitamins, and ])lant growth, 60, 106 



Water-culture, history of, 104 



Water-culture, method, 49, 105-107; plates 20-22 



Water extracts of soil, 6 



Xylem, movement of salts in, 73, 92-95, 98 



Zinc, absorption by alfalfa, 36 



— auxin interrela,tions, 38-40 



— deficiencies for crops, 35, 36, 38 



— deficiencies in soil, 32, 35-36 



— deficiency, cytological effects, 39, 40; plate 15 



— deficiency, relation to climatic conditions, 37-38 



— deficiency, symptoms in plants, 34-35, 37; plates 8, 12, 



13, Ha, Hb 



— effect soil micro-organisms on, 36; plate 13 



— effects on protein synthesis, 40, 41, 42 



— effects on seed formation, 42 



— effects on starch synthesis, 42 



