MAPPING AS AN ECOLOGICAL INSTRUMENT. 
723 
IV. 
MAPPING AS AN ECOLOGICAL INSTRUMENT. 
By Winifred E. Brenchley, D.Sc., F.L.S., 
Fellow of University College, London. 
(Rothamsted Experimental Station). 
Read February 24th. 1914. 
The science and art of mapping have undergone considerable 
change and development during recent years. In the older 
conception of things the “ map ” was an end in itself, and the 
methods and work involved led up primarily and solely to 
the production of the map, beyond which no further advance 
was deemed possible or necessary. This idea still lingers in 
many minds, but it is gradually being supplanted by the wider 
conception of the map as a means to an end — a graphical 
representation of facts from which other facts and hypotheses 
can be deduced, and upon which theories established on a firm 
basis can be built. 
If this wider view of mapping be accepted, it is possible 
to extend its application very considerably, while at the same 
time much more catholicity of interpretation of the maps is 
rendered practicable, so that this method of representing facts 
becomes one of the most useful instruments in the hands of 
the scientific worker. The scope of the method admits of a 
variety of pictures being made of one and the same area, each 
picture representing a different series of facts, thus enabling 
useful comparisons to be instituted between the various factors 
concerned. For instance, such a series may show the physical 
features, the distribution of the different types of vegetation, 
the contour of the ground, and the variety of soils present ; 
in some cases two series of facts may be judiciously combined 
and indicated on the same map — the physical features and the 
distribution of vegetation types being a very usual combination. 
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