PLATE VI 



(a) A typical animal community in the plankton of a tarn in the English Lake 

 District. Three important key-industry animals are shown : Diapto7nus, 

 Daph/iia, and Bosinina. 



{p) Effect of " rabbit pressure " on grass and furze on the Malvern Mills. The 

 plants are closely nibbled by rabbits. The white web on the furze bush 

 was constructed by a minute mite {Erythrceus regalis, Koch, var.) 

 which was present in enormous numbers. 



