484 DR MATTHEWS DUNCAN ON THE VARIATIONS OF THE FERTILITY 



between the ages of 15 and 29 inclusive, one in 2-6, or 38-4 per cent., bore a living 

 child ; and of those between the ages of 30 and 44 inclusive, one in 51, or 19-6 

 per cent., bore a living child. 



Chapter IV. — The Initial Fecundity of Women at Different Ages. 



In commencing the statistical inquiry whose results I am now giving, my 

 object was to discover the fecundity of women at diiferent ages, and I now pro- 

 ceed to address myself to this point. 



It is not my object to illustrate the subject of the arrival of young girls at the 

 age of maturity, the change of the girl into the fertile woman. In the case of 

 some peoples, facts might be collected regarding wives so young as to be in a 

 large proportion sterile from immaturity : and their fecundity gradually appear- 

 ing as age advanced, might produce a column of mothers from 10 to 20 years of 

 age, shewing a gradually increasing fecundity of the population at these ages. 

 Even in our tables derived from the data of wives in Edinburgh and Glasgow, 

 some interesting results are to be found, and allowance must be made for a cer- 

 tain amount of immaturity in the wives of from 15 to 20 years of age. But this 

 question of the arrival of girls at maturity is foreign to the present topic. In 

 it all the women are supposed to be mature, and subjected to the conditions 

 essential for procreation. 



The fecundity of individual women is known to vary extremely. Some are 

 very frequently pregnant, and repeatedly, or even constantly, have plural births, 

 and thrive with it all. Under like conditions, other women are absolutely sterile, 

 or a miscarriage or a dead mature child forms the climax of their fecundity, and 

 this little maybe effected at the expense of permanent constitutional exhaustion. 

 Between these extremes of great fecundity and absolute sterility, there is an un- 

 limited series of varying degrees of fertility. On this interesting aspect of the 

 subject of fecundity, the present research throws little light. It is founded on the 

 result of an aggregate of cases, and can show almost nothing as to individuals. 

 It illustrates the fecundity at different ages of women generally, not the individual 

 fecundity of any. 



The table given in last chapter (Table VII.), affords data which cannot be 

 applied to settle the question of the fecundity of women of different ages. For it 

 is evident that among the mass of wives of each succeeding year, or series of years, 

 are included the wives who were once of the former series or part of them — that 

 is, a class of wives whose fecundity has been at least liable to be increased, 

 diminished, or exhausted by procreation, before they have come to form part of the 

 wives in any of the columns after the first. In order to arrive at the fecundity 

 of women or wives of different ages, it is necessary to secure that the condi- 



