ECOLOGICAL SURVEYS 11 



Considerable ecological surveys of marine animal 

 communities round the British coasts have been 

 carried out for the Ministry of Agriculture and 

 Fisheries and the- Fishery Board for Scotland. Of 

 these may be mentioned the analysis of the bottom 

 fauna of the North Sea bv Davis (1923 and 1925) and 

 by Stephen (1923 and 1933) and of the North Sea 

 plankton in relation to herring food by Hardy (1924) 

 and by Savage (1926). Ford and Baker surveyed 

 the sea bottom communities near Plymouth (Ford, 

 1923). 



On land the most comprehensive ecological surveys 

 in Britain have been done for agricultural research 

 purposes. The importance of the plant and animal 

 organisms in relation to soil fertility has been com- 

 mon knowledge smce the publication of Darwin's 

 work on earthworms and soil, and the discovery 

 that nitrifying bacteria are devoured by soil protozoa. 

 Surveys of the animals living in soil of agricultural 

 land (pasture or arable or both) have been carried 

 out at Aberystwvth (Thompson, 1924 ; Edwards, 

 1929), in Cheshire (Cameron, 1913; Morris, 1920; 

 and Buckle, 1921), and at Rothamsted (Morris, 1922 

 and 1927). Most of these studies have been quanti- 

 tative and such soil faunal surveys stand at present 

 as the most exact surveys that exist for any terres- 

 trial animal communities. With them have been 

 combined also certain surveys of animal life in the 

 ground vegetation of pasture land (Cameron^ 1917 ; 

 Morris, 1920). Cameron also included in his survey 

 certain other habitats such as meadow and pasture. 

 The only survey of heathland and woodland that 

 approaches completeness for some groups of animals 

 is that by Richards (1926, also in Summer hayes and 

 others, 1924) for Oxshott Common. In this as also 

 in Hardy's plankton survey of the North Sea a 

 valuable attempt was made to work out the inter- 

 relations of animals as well. The Oxshott survey 

 covered also some other habitats besides those men- 



