394 



SUBJECT INDEX 



Willow, resistance to lack of oxygen in 



soil, 371 



roots penetrating gley horizon, 371 



transpiration, 183 



Wilting, 108 



in relation to water saturation 



deficit, loi-iii 

 Wind and plant growth, 235-244 

 Wind tunnel — growth of Zea and 



Helianthus, 237-243 

 Wind velocity, in Gurgler valley, 1 56, 1 57 

 World Atlas of CUmatic Diagrams, 7, 



8,9 



Wiirzburg (Germany) temperature gra- 

 dient in soil, 79 



Zea mats, growth in wind tunnel, 237 

 Zilla spinosa, root penetration, 204 

 ZUlertal, precipitation, 159 

 Zygophyllum dumosum, 207 



Hfe cycle, 212 



seasonal body reduction, 215 



transpiration, 217 



weight of transpiring body, 



213, 216 



