1894.] Natality as shown from Observations at Budapest. 17 



ditions are fulfilled in newly-married couples, where the physiological 

 factor is nearly exclusively active. I also thus found the degree of 

 physiological natality for different age-combinations. The two curves 

 are very different. The legitimate natality declines after the first 

 child and its fall shows a regular slope. The physiological arrives 

 later at its maximum, remains for some length of time on this cul- 

 minating height, and decreases only at a more advanced age. 



We get thus two degrees of fertility for each age. The difference 

 between the degree of physiological and that of the actual fertility 

 shows, the few cases of procreative exhaustion excepted, the influence 

 of the moral factor. In the somewhat advanced ages this moral re- 

 straint exercises an influence exceeding all expectation. With the 

 mothers of 30 to 35 it reduces the fertility to 78 per cent, (instead of 

 100 per cent.), with those of 43 ^to 2 per cent., i.e., 98/100 of the 

 physiological faculty is suppressed. With men the influence is also 

 very great, though weaker than with women. 



Out of a large number of data here follow some figures to 

 characterise the results : 



For the mother. For the father. 



i ^ t ^ 



The fertility is Actual. Physiological. Actual. Physiological. 



at 25 to 29 years 29'2 p.c. 30'9 p.c. 35*8 p.c. 28'0 p.c. (?) 



30 34 .... 20-6 32-9 27'1 27-0 

 40 44 . . . . 5-9 20-4 13'8 21-1 



The tables containing the fertility of each sex separately I call 

 monogenous, the others bigenous. Here follow some samples of the 

 bigenous tables : 



For husbands of 39 years of age the probability of becoming fathers 



is : 



with a wife of 20 years 31 p.c. 



30 20 



For husbands of 40 years of age : 



with a wife of 35 years 27 p.c. 



40 17 



45 ......... 21,, 



I attach a volume of tables containing all the probabilities found, 

 and an atlas of diagrams to make this heavy mass of figures more 

 accessible. 



VOL. LV. 



