Per cent that population in each quinquennial period makes of the arithmetical mean of population in the next younger and next older period.

Inspection of this table shows that, throughout, the females depart more widely than the males from the normal of 100 per cent, but that this difference between the two sexes, while constant, is comparatively slight up to the age of 50 years. Thereafter it is very striking.

Corroborative evidence may be found in examining which sex was more fond of reporting the age as exactly 20. In a stationary population about 20.3 per cent of all persons between 20 and 25 are actually 20, but in Porto Rico 32.3 per cent of the males and 34.8 per cent of the females 20-24 reported themselves as 20. This shows that women's tendency to answer in round numbers even at this early age is a little higher than men's.

One may safely conclude that erroneous statements of age, at least after middle life, are more common among Porto Rican women. Where errors of age occur during the later years, they are likely to exaggerate the real age. For example, in the United States in 1890, among every 100,000 colored, 128 claimed to be 90 years old or more, but among every 100,000 native whites of native parents, only 45 claimed to be 90 or more, yet the whites certainly live longer. As elderly Porto Rican women are more prone to report their ages in multiples of 10, so they are probably more prone to exaggerate their age, and part of the high proportion of women 70 years old or more may be thus explained. At the same time, as general experience testifies to a somewhat lower mortality of women in civilized countries, the greater proportion of women in the later ages may probably be accepted as correct, although the census figures exaggerate the difference.

RACE.

[See Tables V, VII, and IX.]

With reference to race, the population of Porto Rico is divided by the census into two main classes-those who are and those who are not pure whites, or Caucasians.

The number belonging to each of these two classes is as follows:

The word "colored" in the preceding table includes a very few (75) Chinese and many persons of mixed white and negro blood, as well as the pure negroes. Somewhat more than three-fifths of the population of Porto Rico are pure white, and nearly two-fifths are partly or entirely negro. In the following table the proportions of white and colored in other West India Islands are given for comparison:

These are all the West India islands for which the facts regarding race were accessible. The table shows that the two islands of Cuba and Porto Rico are exceptional in having a majority of whites. In all others the colored are more numerous, and in all except the Bermudas and Bahamas, both of which lie north of the sugar-producing islands, they are at least ten times more numerous than the whites. The other West India islands have a far smaller proportion of whites than any American state, but there are several American states with a smaller proportion of whites in 1890 than Porto Rico had in 1899. They are as follows:

All the American coast states from Virginia to Louisiana, inclusive, except North Carolina, had a smaller proportion of whites than Porto Rico.