MIDGES 171 



mild example of this phenomenon. The whole 

 sub -Arctic belt of Europe, Asia, and America, is 

 infested with blood-sucking members of the gnat 

 family, and in summer in Lapland they fill the 

 air in clouds till man and deer can hardly breathe 

 it without inhaling them. The finest army is 

 clumsily equipped for war compared with their 

 equipment for boring skins and drawing blood, 

 but the overwhelmingly great mass of them never 

 get any blood to draw. To account for the 

 evolution of their armature, now seen in the almost 

 complete absence of the means of exercising it, 

 is one of the innumerable problems on which the 

 speculative naturalist is invited to beat his brains. 



