42 



POPULAR SCIENCE MONTHLY 



among their non-Jewish neighbors. It is of importance now to in- 

 quire what are the effects of these low rates on the increase of the 

 Jewish population. Population increases, as is well known, by the 

 excess of the number of births over deaths, and it is important to in- 

 quire whether the small birth rates of the Jews are everywhere com- 

 pensated by the low death rates, or whether even their low mortality is 

 insufficient to leave a substantial surplus because the number of births 

 is so small as to be insufficient to replace those lost annually by deaths. 



In general terms it can be stated that there are two ways by which 

 a population may replace its losses by deaths : First, by a high birth 

 rate much in excess of the death rate. This is usually the rule in com- 

 munities in a low state of culture, among agricultural classes, and also 

 among the poorer and laboring classes in European and American 

 industrial centers. The death rate, especially the infant mortality, 

 is very high, but this is compensated by early marriages, and a sub- 

 stantial prolificacy. On the whole, the average duration of life is, in 

 such communities, comparatively short ; the population is being renewed 

 at frequent intervals. 



Communities in a higher state of culture, on the other hand, have 

 generally lower birth, marriage and death rates, particularly the infant 

 mortality is more favorable. It requires a longer period of time for 

 such a community to renew its population, because the average duration 

 of life is superior. This is observed generally among the upper ten 

 thousand of modern civilized states, particularly in large cities. From 

 a sociological and economic standpoint this method of perpetuation 

 of the population, if kept within certain limits, has its advantages 

 over the former method. To use Spencer's terminology, it decreases 

 the expenditure on genesis, leaving sufficient for individual evolution. 

 In other words, the smaller the number of children born has as a con- 

 comitant a smaller infant mortality, and also gives the parents an 

 opportunity to raise their offspring on a more desirable standard. 



A glance at the figures brought together in the preceding studies 

 shows that the Jews, judged by the social and economic environment 

 in which we found them, can be placed in either one of the mentioned 

 classes of fertility. To begin with the natural increase, i. e., the an- 

 nual excess of births over deaths per 1,000 population, it is found that 

 there are great differences between eastern and western European Jews. 



