MAN'S FIGHT 1011 SURVIVAL 625 



104,000,000 in this country, it is estimated that over 30,000,000 had 

 influenza. While much work has been done to discover the causative 

 organism of influenza, the fact that the organism works in conjunc- 

 tion with several others, including the pneumococcus germ, has made 

 it difficult for the disease to be fought by means of vaccines or im- 

 mune sera. At present these two diseases may be named among the 

 most serious enemies of mankind. 



Although it is impossible to do more than mention the many diseases 

 caused by bacteria, emphasis should be placed on the fact that among 

 the most common infections are those caused by the Streptococceae. 

 Pneumonia, septic sore throat, which often appears in severe epi- 

 demics, erysipelas, and apparently catarrh and some forms of colds 

 are caused by them. The StapJujlococci are responsible for boils and 

 abscesses. A member of the genus Neisseria causes gonorrhea and 

 probably cerebro-spinal meningitis. Anthrax, tetanus, whooping 

 cough, gas gangrene, cholera, bubonic plague, Malta fever, one type 

 of dysentery, and hundreds of other diseases are due to specific forms 

 of bacteria. 



What Is Immunity? 



It is a matter of common knowledge that certain members of a 

 family will have a very light attack of a communicable disease while 

 the others may suffer severely from it. Some may be exposed many 

 times to a given disease and not take it, while others, who are more 

 susceptible, will come down with the disease. This resistance on the 

 part of the body to disease is called immunity. Adults are practically 

 immune to certain children's diseases, such as measles, chicken-pox, 

 and scarlet fever. On the other hand infants appear to be immune, 

 especially early in life, to both diphtheria and measles. A theory 

 has been advanced that this early immunity is restricted to breast- 

 fed babies because the material (colostrum) secreted in the mother's 

 breasts shortly after childbirth contains substances w^iich protect 

 the child against these and other early infections. 



Eskimos, Indians, the Irish, Scandinavians, and Negroes are very 

 susceptible to tuberculosis, while Jews are relatively immune to this 

 disease, probably due to the fact that the American Jews have lived 

 an urban life where they have been constantly exposed to tuberculosis 

 and so have built up an immunity to it. The inhabitants of the Fiji 

 Islands were almost wiped out by exposure to measles, a relatively 

 mild disease to the European. The Negro seems to have a natural 



