Statures of Toronto girls, grouped in one-year periods.

Statures of Toronto girls, grouped in one-year periods-Concluded.

Number of girls measured of the age of

Height in centi

meters.

150.

151

152.

153.

154.

155.

156.

157

158.

159.

160.

161

162

163.

164.

165.

166.

167

168.

169.

170.

171

172.

173.

174.

Corrected average.

759 834 875 822 876 824 665 6.508 7.508 8.475 9.475 10. 483 11. 475 12. 458 13. 458 14. 442 15. 433 16.358 100.4 105.2 110.4 116.0 120,6 125.2 130.8 136.0 441.7 147.7 153.0 155.8 156.5 14.26 ±4.80 ± 4.80 ± 5.30 +5.53 +5.32 ±6.20 ± 6.52 ±6.96 17.17 ±6.35 ±5.86 ±5.35 110.4 116.0 120.7 125.3 130.9 136.1 141.9 148.0 153.3 156.0 156.7

The following table exhibits the statures of Toronto children as compared with American children in general:

106.2 111.1 116.8 121.8 126.7 131.5 135.9 140.1 145.4 151.5 157.6
105.9 111.6 116.8 122.0 126.9 131.8 136.2 140.7 146.0 152.4. 159.7

STATURES OF GIRLS, IN CENTIMETERS.

105.2 110.4 116.0 120.7 125.3 130.9 136.1 141.9 148.0 153.3 156.0 156.7 104.9 110.1 116.1 121 2 126.1 131.3 136.6 142.5 148.7 153.5 156.5 158.0

VARIABILITY OF BOYS' STATURES.

+5.12 +4.82 ±5.08 ±5.58 +5.59 ±6.15 ±6.15 ±6.80 17.79 ±8.55 ±9.00
±4.80 +4.92 ±5.22 ±5.53 ±5.66 ±5.90 ±6.32 +6.80 +7.71 ±8.66 +8.87 £7.75

VARIABILITY OF GIRLS' STATURES.

Toronto

American

+4.80 +4.80 ±5.30 +5.53 ±5.32 ±6.20 +6.52 ±6.96 ±7.17 ±6.35 ±5.86
14.64 ±5.07 +5.25 +5.58 ±5.73 ±6.18 ±6.83 ±7.57 ±7.37 ±6.69 ±5.96

+5.35

£5.79

It appears from these tables that on the whole the Toronto children are not afavorably developed as are American children, their statures being slightly shorter. The variability of the Toronto series does not differ so much from the genera series as might be expected. The causes that modify the growth of children in a single city appear to be so great that the decrease in general variability is very slight indeed.

The variabilities given in the preceding tables are those for the whole year. When the variabilities for each year are calculated from the averages of the trimonthly periods given on pages 1558-1564, a considerable reduction in the values takes place.

BOYS.

Variability for

The whole year

Quarterly

Age in years.

5.5. (6.5. 7.5. 8.5. 9.5.

10.5. 11.5. 12.5. 13.5. 14.5. 15.5. 16.5.

+5.12 ±4.82 ±5.08 +5.58 ±5.59 ±6.15 +6.15 ±6.80 ±7.79 ±8.55 +9.00 periods... +4.70±4.65±4.77 ±5.38 +5.35 +6.02 16.08 ±6.61 ±7.63 +8.22 a±8.91

GIRLS.

The whole year +4.80 +4.80 15.30 ±5.53 ±5.32 16.20 ±6.52 ±6.96 ±7.17 16.35 15.86 ±5.35 Quarterly periods +4.62 14.73 ±5.21 ±5.34 ±5.18 ±5.89 ±6.38 ±6.90 ±6.85 ±6.13 +5.73 +5.63

a Six-monthly period.

THE GROWTH OF FIRST-BORN CHILDREN.

I have shown (Science, 1895, April 12) that the first-born children in Oakland, Cal., exceed in height later-born children. The data which were then available gave the following results. The columns headed "Differences" contain the amount to be added to the average statures and weights in order to obtain the measurements of first-born and later-born children. The figures in parentheses designate the number of individuals measured.

The following tables contain the detailed results of the measurements obtained in Toronto:

1981

124122

3

1