150 ACS-INCIDENCE OF CAUSES OF INFANT MORTALITY 



very fatal indeed, but infertile, insomuch that measles, whooping 

 cough, scarlet fever and diphtheria regularly fail to attack in- 

 fants in proportion to their numbers, except under conditions of 

 institutional or other unnatural promiscuity of infants. 



Within the area of infancy, babies themselves are all but im- 

 potent as mediators of infantile sickness. Here the respon- 

 sibility is divided between mediations of childhood and media- 

 tions of parenthood. Without these two kinds of mediation the 

 precincts of infancy would be almost inviolable. 



But the space of infancy, isolated as it is, is subsequent to 

 another more isolated the biologic inclusion of prenatal exist- 

 ence; and this, in turn, is subsequent to another inclusion, hav- 

 ing investments of civil, social, and religious order. These 

 several investments enclose the reproductive group, into which 

 young adults are admitted by twos, and counted as ones. 

 It is not a very large group, being less than one-fourth of 

 the total population. The function of this select group is to 

 generate both the numbers and the characteristics of the fol- 

 lowing generation ; and for this purpose the vitality of the group 

 must be exalted to an amount exceeding current losses of the 

 total population far enough to assure the presence, in the next 

 generation, of a superior group of adolescents, from which a sup- 

 erior reproductive group may be selected. Under existing con- 

 ditions, to raise the common stock of vitality to such a power, 

 calls for a gestative effort on the part of about five and a half 

 per cent, of the population each year (2,500,000 wives in the 

 Registration Area). Such a gestative effort will yield an ap- 

 parent increment of 3.5 per cent, on the total population ; enough 

 to withstand a heavy mortality and still provide a superior group 

 of candidates for another reproductive group 18 or 20 years 

 later. The gross fertility of 3.5 per cent, is about twice 

 that required at the beginning of the next reproductive cycle, 

 and when that time arrives it is likely that one-half of the new 

 reproductive group will be the fruition of one- fourth of the 

 parent group. At its best the gestative effort calls for a very 

 severe extension of the vitality of women, impossible to be 

 achieved without sensibly disturbing the vitality of the whole 

 population within the same age period. 6 The formation of a 

 social inclusion around the reproductive group signifies a pur- 

 pose to create and maintain a reserve of vitality for the benefit 

 of the select few whose individual vitality is to be so severely 

 extended. 



6 In this connection it is interesting to note that Elderton, having a'ssumed 

 the normal curve of error as an exposed-to-risk curve, and having applied the 

 unit of sickness experience, obtained a sickness curve with two maxima, the 

 minor mode at 38 and the major mode at 67 years of age. 



