NO. 630] HUMAN MORTALITY BATES 



17 



in general terms, that on any proper biological basis 

 deaths coming under either of these two categories are 

 not properly chargeable organically against the infant 

 at all, but should be charged, on such a basis, against the 

 mother. To go into further detail, it is apparent that 

 when a premature birth occurs it is because the reproduc- 

 tive system of the mother, for some reason or other, did 

 not rise to the demands of the situation of carrying the 

 fetus to term. Premature birth, in short, results from a 

 failure or breakdown in some particular of the maternal 

 reproductive system. This failure may be caused in 

 various ways, which do not here concern us. The essen- 

 tial feature from our present viewpoint is that the repro- 

 ductive system of the mother does break down, and by so 

 doing causes the death of an infant, and that death is 

 recorded statistically under this title "Premature birth." 

 The death organically is chargeable to the mother. 



4- considerable number of cases of premature birth are 

 unquestionably due to placental defect and the placenta 

 is a structure of fetal origin, so such deaths could not be 

 properly charged io the mother. On the other hand, 

 however, they would still stay in Table III, because the 

 placenta may fairly be regarded as an organ intimately 

 concerned in reproduction. 



The same reasoning which applies to premature births, 

 mutatis mutandis, applies to the item "Injuries at birth." 

 An infant death recorded under this head means that 

 some part of the reproductive mechanism of the mother, 

 either structural or functional, failed of normal per- 

 formance in the time of stress. Usually "injury at birth" 

 means a contracted or malformed pelvis in the mother. 

 But in any case the death is purely external and acci- 

 dental from the standpoint of the infant. It is organ- 

 ically chargeable to a defect of the sex organs of the 

 mother. The female pelvis, in respect of its conforma- 

 tion, is a secondary sex character. 



A practical difficulty arose from the fact that in the 

 Sao Paulo statistics items 151 and 152 are not subdivided. 



