LIST OF ILLUSTEATIONS 



PIG. 



1. Crops gi'own on partially sterilised soils 



2a and 2b. Experiments with Rock Phosphate, 

 Illinois (Dr Cyril Hopkins) .... 



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



Hutchinson) 



4. Reclaimed Fenland (Mr B. R. Dixon) . 



5. Taking levels for draining in Puritan times . 



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



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



8. Coxheath, near Maidstone .... 



9. Pot Culture house at Rothamsted . , 



