LIST OF ILLUSTRATIONS 



FIG. 



1. Crops grown on partially sterilised soils . to face p. 26 



2 a and 26. Experiments with Rock Phosphate, 



Illinois (Dr Cyril Hopkins) 47 



3. The Wilderness, Rothamsted (Dr H. B. 



Hutchinson) 65 



4. Reclaimed Fenland (Mr E. R. Dixon) . . 72 



5. Taking levels for draining in Puritan times . 76 



6. Chalking in Hertfordshire (Dr H. B. Hutchinson) 82 



7. Ridged land on the clay (Mr H. Cranfield) . 90 



8. Coxheath, near Maidstone .... no 



9. Pot Culture house at Rothamsted . 126 





