86 Disease and Immunity 



grows weaker and weaker until finally he dies 

 from sheer exhaustion. 



The distinction here is between a load and an 

 overload. If the load is something more than it 

 was before, and is continually increased but never 

 raised to the point of becoming an overload, 

 the man, or other animal or plant, continues to 

 gain in powers for an indefinite period. If the 

 load is raised to an overload, then the man be- 

 comes progressively weaker. This last is, in its 

 essence, the same as disease. 



Several examples of the development of 

 powers were given in a preceding chapter. A 

 few more given at this point will help in an 

 understanding of the relation of powers to health 

 and disease, and to everything which makes life 

 worth living. 



The flagellata are unicellular animals. During 

 a period of about six years Dallinger subjected 

 these animals to gradually increasing tempera- 

 tures. B^^inning with those normally living in 

 water at 60 d^ees Fahr., he found that they 

 began to die as soon as the temperature rose 

 above 73 d^rees. But by holding the tempera- 

 ture for about two months at this point he found 



