72 
STA TISTICS: PEARL AND B URGER Proc. N. A. S. 
value, li V > 100 the population is not only surviving but growing, 
whereas if V < 100 the population is starting on the road to elimination, 
and must eventually disappear unless the vital index gets above 100. 
A detailed presentation of the facts regarding the vital index of certain 
elements of the American population has lately been published.^ 
In examining the effect of the Great War upon the growth of population 
one cannot fail to be impressed by the fact that the return of the birth/death 
ratio (vital index) to a normal or even super-normal value after the marked 
dislocation produced by the war, and at its end the superimposed influenza 
pandemic, was extraordinarily rapid. Indeed the senior author* was led to 
remark, after examining the matter in the chief belligerent countries, that 
"Altogether, these examples, which include the effects of the most 
destructive war known to modern man, and the most devastating epidemic 
TABLE 1 
Ratio V, of 100 Births to Deaths in England and Wales in Bach Quarter 
OF the Years 1838 to 1920, Inclusive 
QUARTERS ENDED 
QUARTERS ENDED 
QUARTERS ENDED 
YEAR 
MAR. 
JUNE 
SEPT. 
DEC. 
YEAR 
MAR. 
JUNE 
SEPT. 
DEC. 
YEAR 
MAR. 
JUNE 
SEPT 
DEC. 
1838 
116 
134 
157 
140 
1866 
142 
150 
153 
158 
1894 
155 
186 
201 
180 
1839 
138 
146 
157 
141 
1867 
145 
178 
176 
158 
1895 
141 
179 
174 
161 
1840 
134 
143 
148 
135 
1868 
166 
184 
147 
160 
1896 
163 
185 
181 
168 
1841 
135 
151 
164 
150 
1869 
153 
159 
166 
149 
1897 
164 
179 
169 
170 
1842 
141 
155 
150 
148 
1870 
143 
168 
155 
151 
1898 
154 
183 
166 
169 
1843 
144 
150 
167 
150 
1871 
151 
167 
159 
144 
1899 
157 
182 
151 
152 
1844 
142 
160 
163 
143 
1872 
155 
173 
170 
176 
1900 
132 
166 
175 
167 
1845 
137 
153 
177 
163 
1873 
163 
174 
178 
160 
1901 
158 
182 
169 
167 
1846 
162 
166 
136 
128 
1874 
157 
176 
169 
150 
1902 
153 
179 
209 
168 
1847 
122 
130 
136 
123 
1875 
132 
164 
174 
159 
1903 
170 
195 
207 
169 
1848 
116 
150 
160 
144 
1976 
162 
179 
180 
177 
1904 
157 
192 
178 
165 
1849 
145 
150 
100 
139 
1877 
171 
170 
195 
177 
1905 
160 
192 
195 
172 
1850 
147 
168 
171 
159 
1878 
158 
177 
172 
155 
1906 
169 
189 
181 
166 
1851 
149 
160 
165 
150 
1879 
145 
167 
210 
160 
1907 
143 
187 
216 
161 
1852 
152 
158 
151 
152 
1780 
152 
186 
167 
165 
1908 
153 
201 
208 
170 
1853 
137 
147 
160 
140 
1881 
163 
186 
196 
177 
1909 
143 
189 
218 
172 
1854 
144 
168 
136 
133 
1882 
159 
182 
186 
163 
1910 
163 
203 
218 
168 
1855 
123 
155 
177 
153 
1883 
158 
171 
189 
167 
1911 
156 
188 
158 
169 
1856 
164 
173 
173 
164 
1884 
170 
181 
167 
165 
1912 
154 
188 
216 
170 
1857 
157 
170 
160 
146 
1885 
157 
168 
191 
173 
1913 
148 
187 
199 
172 
1858 
136 
158 
160 
133 
1886 
147 
184 
179 
168 
1914 
149 
182 
197 
159 
1859 
144 
166 
161 
155 
1887 
153 
176 
178 
163 
1915 
125 
154 
180 
134 
1860 
149 
157 
190 
158 
1888 
149 
179 
199 
169 
1916 
136 
165 
193 
134 
1861 
143 
172 
170 
159 
1889 
158 
183 
180 
165 
1917 
109 
136 
172 
136 
1862 
149 
173 
187 
160 
1890 
136 
171 
180 
139 
1918 
118 
144 
147 
67 
1863 
145 
160 
154 
155 
1891 
145 
139 
192 
156 
1919 
75 
137 
197 
195 
1864 
135 
161 
161 
144 
1892 
120 
176 
197 
168 
1920 
197 
208 
245 
180 
1865 
138 
167 
160 
148 
1893 
160 
177 
160 
147 
