The anthropometric examinations given in the University of Porto Rico during the last two years have provided data from which to determine the physical development of the Porto Rican. A total of 1,412 examinations has been made, including 616 men and 796 women. These students ranged in age from fifteen to thirty years.

A comparison of the physical development of American and Porto Rican boys and girls of the same age shows that the Porto Rican surpasses the American in nearly every point, at the ages of fifteen, sixteen, and seventeen. At eighteen the physical development is about the same, but from that time there seems to be little additional growth on the part of the Porto Rican, while the American continues to develop up to and including the twenty-second year. This seems to confirm the generally accepted theory that a person matures earlier in the tropics than he does in a temperate climate. That the slighter physical development is the effect of geographic or climatic conditions, and is not entirely due to race, is proved by the fact that measurements of Chilean boys, who are of Spanish blood, more nearly approximate those of North American boys than they do those of Porto Ricans. The following tables show a comparison of the development of the Porto Rican students with the average development of American men and women. The measurements are in pounds and inches.

Table I
Average measurements
of Porto Rican male
students from 16 to 28
years of age		Average measurements
of American men
from 17 to 30
years of age
Height 64.94 67.6
Weight 110.67 138.6
Chest, transversal 10.26 10.8
Chest, anterior-posterior 7.92 7.5
Shoulders 15.06 16.1
Neck 13.05 13.9
Chest, contracted 30.63 33.7
Chest, expanded 33.25 36.7
Waist 27.92 29.1
Right forearm 9.33 10.4
Left forearm 9.20 10.4
Right arm up 9.61 11.9
Right arm down 8.45 10.4
Left arm up 9.42 11.8
Left arm down 8.22 10.3
Right thigh 17.97 20.3
Left thigh 17.83 20.2
Right calf 12.64 13.8
Left calf 12.66 13.8

Table II
Average measurements
of Porto Rican women
students from 16 to 28
years of age		Average measurements
of American women
from 17 to 30
years of age
Height 61.78 62.9
Weight 107.82 116.0
Chest, transversal 9.35 10.0
Chest, anterior-posterior 6.93 6.8
Shoulders 13.64 14.4
Neck 11.98 12.1
Chest, natural 29.19 29.7
Chest, contracted 28.57 29.6
Chest, expanded 31.29 32.0
Waist 25.14 24.3
Hips 33.76 35.7
Right forearm 8.71 8.8
Left forearm 8.61 8.6
Right arm down 8.44 9.8
Left arm down 8.40 9.7
Right arm up 8.99 10.8
Left arm up 8.82 10.6
Right thigh 18.79 21.1
Left thigh 18.65 21.0
Right calf 12.66 13.0
Left calf 12.64 13.0

If it is true that the Porto Rican reaches the height of physical development at the age of eighteen, then we may consider that an average of the measurements of the men and women from and after that age will give us what is practically the representative physical development of the Porto Rican adult. These averages are found in the following table.

Table III
Representative development of Porto Rican students at the University of Porto Rico, of more than 18 years of age.

MenWomen
Height65.8761.83
Weight116.21107.93
Shoulders15.3913.67
Chest, transversal10.399.34
Chest, anterior-posterior8.076.98
Neck13.3212.01
Chest, muscular32.7430.27
Chest, natural31.8729.45
Chest, expanded33.8431.30
Chest, contracted31.3628.23
Waist27.9625.08
Hips32.1333.45
Right arm down8.628.49
Right arm up9.798.95
Right forearm9.538.61
Left arm down8.438.36
Left arm up9.618.83
Left forearm9.468.29
Right thigh18.3818.76
Left thigh18.1518.61
Right calf12.8512.68
Left calf12.9012.64

For the purpose of comparing the Porto Rican boys with boys of Spanish blood, but of another climate, Table IV, which shows the comparative development of Porto Rican and Chilean boys from 16 to 20 years of age, is given. The measurements for the Chilean boys were furnished by the Museo Nacional of Santiago, Chili.