ECONOMIC PROBLEMS 83 



Math sport. Two special economic aspects of con- 

 servation are sport (the production of good game 

 crops and forecasting of bad ones) and the fur trade 

 (in which both conservation of supphes and fore- 

 casting of fluctuations are important). Special atten- 

 tion to game problems has been given in Norway 

 (the willow grouse), in New England and other parts 

 of United States (grouse and quail), and in England 

 (red grouse, partridge, etc.). The fur trade is a 

 world-wide industry, but its fluctuations have been 

 more especially studied in the Arctic regions and in 

 the great conifer belt of the northern hemisphere 

 (Canada, Alaska, Siberia, Russia, and Norway). 

 Summaries of some of these investigations are given 

 by Hewitt, 1921 ; Elton, 1924, 1931 ; Formosof, 

 1933 ; Johnsen, 1929. 



To a certain extent these difi'erent economic prob- 

 lems interact. The conservation of game animals in 

 Africa has had to reckon with the theories (probably 

 incorrect) of medical investigators, who wish to wipe 

 out game in order to destroy the reservoirs of nagana 

 and sleeping sickness. White foxes are the most 

 valuable furs in the Arctic, but their periodic disap- 

 pearance is accompanied by epidemics which are 

 apparently responsible for fatal disease in sledge 

 dogs. Rats attack stored products and carry plague. 

 Human diseases Umit the areas in the tropics where 

 white men can farm at all. River pollution affects 

 both fisheries and water supphes. And so on. 



We now hav9 to consider the relation of ecological 

 science to these problems. In the main we may 

 say that the first important task of ecologists is to 

 obtain accurate information. It frequently happens 

 that practical policies of control of pests or fishing or 

 methods of hygiene are based on fallacious precon- 

 ceived ideas about the ecology of the animals. Thus 

 the U.S. Fish Commission for many years bred 

 marine fishes in aquaria and put them into the 

 Atlantic Ocean to remedy a scarcity of fish which was 



