WAYS AND MEANS 



than upon a hill-top, or a dry plateau, re- 

 mote from any stream? How do they 

 come there, and what do they seek? These 

 are among the many questions which aver- 

 age ignorance cannot answer. An incred- 

 ibly small number of these creatures must 

 find conditions allowing reproduction; 

 otherwise man would be driven from the 

 woods. The Anticosti flies used to harry 

 Mr. Menier's cows into early graves. 

 These unhappy ones were the only four- 

 footed mammals on the island, except 

 bears — whose ancestors probably arrived 

 on ice-floes or drift, — foxes, otters, martens 

 and mice. The owner disturbed the bal- 

 ance of nature, not with any kindly thought 

 of the flies but for his own purposes, by 

 introducing caribou and hares; an unex- 

 pected by-ef¥ect has been the shifting of the 

 flies' attentions to the hares, and the conse- 

 quent survival of the cows! There is a 

 marked variation from season to season in 

 the size and (I think) the disposition of 

 the swarm: may it not be that in a good 

 year for hares we are less troubled by the 

 common enemy? Conversely, is there not 

 a relation between the falling off among 

 the hares every seventh year and the flies' 



activity? 



249 



