relation to the Soils on which they grow . II. 109 
the same association with particular types of crop in Bedfordshire and in 
the West Country. 
3. The relative prevalence of the weeds varies somewhat in the different 
districts, certain species which are more or less common in one place being 
practically absent or very scarce in another, on similar soils. 
In conclusion I wish to tender my thanks to Mr. E. S. Beaven, who 
has given me every possible assistance, both by putting me into touch with 
various farmers, and by the personal interest that he has taken in the work, 
together with much friendly advice and criticism. Also I must express my 
indebtedness to all those whose land came under investigation, for their 
unfailing kindness and readiness to facilitate the work. 
