1378 
The percentage of quick workers increases regularly with age 
for the boys and girls separately and for the two sexes collectively, 
that of the slow workers lessens regularly. As to the fairly quick 
workers the change in their percentage is not regular, neither for 
the boys nor for the girls. The moving up from slow to fairly quick 
workers is among the boys, with the exception of boys of from 8 
to 9 years, invariably less considerable than from fairly quick workers 
to quick ones. Among the girls, on the other hand, the transition 
from the fairly-quick to the quick workers is more marked only 
from 10—11 and from 11 to 12 years of age. The difference in 
this respect between boys and girls manifest itself still more distinctly 
by the fact, that of the 50°/, decrease in the percentage of slow 
workers among the boys from 8—12 years, 44 °/, falls to the benefit 
of quick workers and 6°/, to the fairly quick-ones; for the girls 
these values are respectively 32°/, and 34 °/ 
This has been tabulated in 
TABLE VI. 
Boys Girls Children 
Age (years) ; : d 
Quick an ‘Slow Quick Bad ‘Siow Quick ae | Slow 
8—9 Tig Ief | gore: | 412 | {2 |e 4E ae gy 
go 18) tg’). 259 | Sgn 6 VU TRON or 5 NE 
10= 11 — |) eat) EEG | fg (ie!) tg Gig Nitti 6 | ws 
ese de | i” es Gia Sn eN Nee | 14.5 
ns | 
ean +44] +6 | —50 || +32| +34 | —66 |l+38 | +20 se 
It illustrates how the decrease in the number of slow workers 
for the boys and girls separately and for the two sexes collectively 
benefits the groups of quick and fairly quick workers. The values 
were obtained. by calculating the difference, positive and negative, 
of the percentage of the quick, the fairly quick, and the slow 
workers in two successive years. For each of the three several 
groups the algebraic sum of these differences expresses the increase 
or the decrease of the percentage of the quick, and the slow workers 
in the five years. 
