MAN'S FIGHT FOR SURVIVAL 609 



The discovery of the importance of disease carriers, both insect and 

 human, has played an miportant part in the improvement of Uving 

 conditions, while even more important is the advance of knowledge 

 in relation to immunity and the factors which bring it about. The 

 life span has steadily advanced as a result of these and other discover- 

 ies and their applications, a gain brought about largely through the 

 mastery of disease caused by bacteria, especially those diseases which 

 are fatal to young children. 



Since the question of the survival and progress of civilization 

 depends upon a knowledge of the means of successful control of disease 

 and preservation of health, a study of man's fight for survival should 

 be of the greatest value to college students, who later must take their 

 places as intelligent citizens and voters. Upon their knowledge of the 

 facts concerning the successes in this battle against parasites and 

 disease, further progress will depend. 



Although our knowledge should be preventive rather than curative, 

 since it is the duty of the physician to take care of the disease when 

 it comes, the average citizen ought to be well informed enough to 

 answer all of the following questions intelligently. What are the 

 causes of disease? Which parasites do man most bodily harm? 

 Where is he most likely to meet them and how may he prevent their 

 attacks? What are the facts about human carriers? Do present 

 laws adequately protect man against them? What is natural 

 immunity and how does the body protect itself? What is the 

 present status of protective immunity and what are the ways in Avhich 

 man may bring it about ? These questions are taken up in the pages 

 that follow. 



What Is Health? 



Health is evidently something to be sought after as a primary ob- 

 jective of life. The old Anglo-Saxon word, hoelth, from which the 

 word health is derived, meant ivhole as opposed to its opposite, soec 

 which meant sick or not whole. The implication is clear. Health 

 is a condition in which body and mind are free from disease. One 

 writer puts health on a higher plane and defines it as "the quality of 

 life that renders the individual fit to live most and serve best." ^ 

 Such a definition gives to life a higher responsibility, and is one 

 that should be adopted by every man and woman. If education 



1 Williams, J. G., Personal Hygiene Applied, Saunders, 1926. 



