156 Brenchley . — The Weeds of Arable Land in relation to 
The working plan adopted was that of visiting as many farms as 
possible during the season (extending from May to August), and detailing 
the nature of the soil, the crop grown, and every weed found in each 
individual field. So far as was practicable the relative prevalence of the 
weeds was noted in each case, falling under five headings : — 
(1) Dominant. 
(2) Sub-dominant. 
(3) Very generally distributed. 
(4) Occasional. 
(5) Scarce or rare. 
Much information was frequently obtained from the landowners or 
farmers as to the soil, rotation of crops, manuring, and troublesome weeds. 
The data obtained in the field have been tabulated and analysed. It 
must be fully realized at the outset that what is set forth in this paper is 
essentially preliminary and to a large extent tentative in nature. Of 
necessity the year’s work was confined to a very limited area, and before 
any definite conclusions as to the relations between the weed, soil, and crop 
can be arrived at, the work will need to be extended to embrace more 
numerous geological formations, and also to include the same forma- 
tions in different parts of the country, in order that true comparisons can be 
drawn. It must be borne in mind that this paper simply sets forth the 
results of a careful study of a limited and localized area in one particular 
season. 
During the season’s survey about 150 fields were visited, yielding 10 7 
species of weeds, representing 74 genera. Of these, 30 species, representing 
28 genera, were each seen once only. In noting the weeds those plants only 
growing actually among the crops were taken into consideration, those 
occurring on the banks and hedgerows being ignored. 
The classification of the soil was necessarily somewhat haphazard, as 
no mechanical analyses were undertaken during this preliminary survey, an 
arbitrary opinion on the nature of the soil in each case being formed on the 
field, and frequently modified or corroborated by the verdict of the farmer. 
In the absence of mechanical analyses it is very difficult to distinguish 
between a true clay and a clayey or heavy loam, a sand and a very light 
loam, &c., but experience enables one to gauge the texture of the soil 
sufficiently for the practical purpose of the investigation. 
The more important species of weeds, with their habitats and relative 
dominance, were as follows : — 
Ranunculaceae. Ranunculus acris. Most frequent on chalk and 
light loam ; no record for gravel. Never dominant, and rarely found on 
very sandy soil. 
Ranunculus arvensis. Chiefly found on clay land, but it occurred on 
