252 BIOLOGY OF DEATH 



gives the curve for France. Since before tlie time when 

 definite census records began, France has been a rather 

 densely populated country. All the data with which we 

 had to work, belong therefore, towards the final end of 

 the whole population history curve. The known popula- 

 tion data for France and for the United States stand at 

 opposite ends of the whole historical curve. One is an 

 old country whose population is nearing the upper limit; 

 the other a new country whose population started from 

 near the lower asymptote only about a century and a half 

 agq. But it is seen from the diagram that the general 

 theory of popidation growth fits perfectly the known facts 

 regarding France's population in the 120 years for which 

 records exist. While there are some irregularities in the 

 observation, due principally to the effects of the Franco- 

 Prussian war, it is plain that on the whole it would be 

 practically impossible to get a better fitting line through 

 the observational circles than the present one. 



We have seen that the general theory of population 

 describes with equal accuracy the rate of growth in a 

 young country, with rapidly increasing population, and 

 an old coimtry, where the population is approaching close 

 to the absolute saturation point. Let us now see how it 

 works for a country in an intermediate position in respect 

 of population. Figure 63 shows the population history 

 of Serbia. Here it will be noted at once that the heavy 

 line, which denotes the region of known census data, lies 

 about in the middle of the whole curve. Again the fit 

 of theory to, observation is extraordinarily close. No 

 better fit, by a general law involving no more than 3 con- 

 stants, could possibly be hoped for, 



I think that these three examples, which could be 

 multiplied to include practically every country for which 



