302 



CHARLES HERRMAN 



ratio of deaths in male infants to female infants is low, in winter high. This 

 we should expect, for in the summer the infant deaths are caused chiefly by- 

 digestive disorder, and are due to improper feeding, the use of impure milk, 

 so that the unfortunate infants of the poor and less intelligent are primarily 

 affected. In the winter the deaths are caused chiefly by respiratory infec- 

 tions, against which we have no adequate control, so that the unfit among 

 the intelligent and well-to-do are equally endangered, the selective action is 

 more marked, and the ratio of male to female deaths is higher. As indi- 



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THS 

 TERINE 



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MONTHS 

 EXTRAUTERINE. 



Chart 1. Ante and Post Natal Mortality (Pfaundler) 



cated in chart 2 the sex ratio in digestive diseases is 128 to 100, that in respir- 

 atory diseases is 135 to 100. In early infancy the selective action is most 

 marked, so that the ratio is high, namely 139 to 100. This explains why in 

 spite of great improvement in preventive medicine and in hygiene, the 

 deaths at this period have not been reduced. As the mortality in infancy 

 and childhood decreases, the respiratory infections become increasingly im- 

 portant. Measles, whooping cough and influenza, with the frequently 

 complicating pneumonia, become the chief selective agents (chart 3). 



The statistical data of New York City have the advantage that in addi- 

 tion to the large number of cases, they have been compiled in a uniform 

 manner under the supervision of the same chief of the Bureau of Vital Sta- 



