246 Trans. Acad. Sci. of St. Louis. 
or quickness of growth, given in Table No. 5. The compar- 
ison is made easy by arranging the totals side by side. The 
25 \28 g\ f28 |22_% 
B23 [S3u2| B85 (Bese 
; Bob ino. 21 eo b ie? = 
AGE. Bas Ga a|ee8 ea « 
Boys. | Boys. | Grris. | GIRLS. 
ee rea ee SE Saws a eee EIS 29.2 bese sees 22.1 levee recs 
eae Se ea Gs eas we ecu bs ees 22.7 25.4 23.7 25.9 
Berk. ok ba Fa Meow VES GSMS vb ase se 22.3 24.1 22.3 25.8 
Wey esse fase beseeene seers. 21.8 24.2 22.6 24.8 
Be ec eee Sis da ees oe nv 222 22.7 22.5 21.5 
EE e ee 22.2 21.8 24.4 | 24.9 
oo EER Ry Ga Rega atari Sag 21.8 20.5 24.7 27.9 
RSS ie ng a ne tee ee eee eee 26.1 20.9 | 27.4 33.6 
PERC ELE US ERECT Deepa ace Veen Vokes ere 98.1 96.2 Wie) 24.0 
De ee bee Nees be ev ck es bv CAdee sees sas 29.0 31.6 22.8 22.8 
FO a i 30.0 25.8 20.7 16.2 
Be ee es os vs wk oe eas 22.8 20.5 18.5 12.1 
dd ne eee ee eee 19.0 19.4 17.7 S23 
comparison reveals in both cases a general though not un- 
broken fall from age 7 to age 13 in boys and 11 in girls, a 
remarkable increase covering four years in both sexes, and a 
subsequent great decline. Thus the Relative Deviation co- 
incides in the main with the Quickness of Growth. This 
relation is shown graphically in Plate I 
he phenomena just described are here seen to advantage. 
The curve of rate of growth in boys (unbroken red line) falls 
from age 7 to 12, corresponding to a small fall in Probable 
Deviation (unbroken black line). At age 12 to 13, a sudden 
change appears in both curves. They rise rapidly, reach a 
high maximum and suddenly fall to their former level. The 
period from the beginning of the rise to the return to 
the level of age 12 has the same duration in both curves. 
The maximum deviation is greater in Relative Anuual In- 
crease than in Relative Probable Deviation, a fact in accord 
with the greater stability of the latter, and the maximum 
Annual Increase occurs a little earlier than the maximum 
Probable Deviation. The period of acceleration is more _ 
sharply defined in Annual Increase. At age 18, both curves 
are still falling. The relation between the Rate of Growth 
