MOSQUITOES 65 



relief from the torment. It is easy to get used to 

 those coverings; it is impossible to get used to the 

 mosquitoes. 



For July 10 I find this note: "The Mosquitoes are 

 worse now than ever before; even Jarvis, Preble, and 

 the Indians are wearing face protectors of some kind. 

 The Major has borrowed Preble's closed net, much to 

 the latter's discomfiture, as he himself would be glad 

 to wear it." 



This country has, for 6 months, the finest climate 

 in the world, but 2J of these are ruined by the ma- 

 lignancy of the fly plague. Yet it is certain that 

 knowledge will confer on man the power to wipe them 

 out. 



No doubt the first step in this direction is a thorough 

 understanding of the creature's life-history. This 

 understanding many able men are working for. But 

 there is another line of thought that should not be 

 forgotten, though it is negative — ^many animals are 

 immune. Which are they? Our first business is to 

 list them if we would learn the why of immunity. 



Frogs are among the happy ones. One day early in 

 June I took a wood-frog in my hand. The mosquitoes 

 swarmed about. In a few seconds 30 were on my 

 hand digging away; 10 were on my forefinger, 8 on my 

 thumb; between these was the frog, a creature with 

 many resemblances to man — red blood, a smooth, 

 naked, soft skin, etc. — and yet not a mosquito attacked 

 it. Scores had bled my hand before one alighted on 

 the frog, and it leaped off again as though the creature 

 were red hot. The experiment repeated with another 



