416 HALBERT L. DUNN 
Having obtained calculated values for the different measure- 
ments under consideration, tables of each dimension were drawn 
up in some detail. ‘These are tables 1, 3, 7, 9, 11, 13, 15, 17, 19, 
21, 23, 25, 27, 29, 31, 33, 36, 38 of the present publication. In 
each of these is given the crown-heel length in 5-cm. intervals, 
the average crown-heel length, the maximum, minimum, and 
arithmetic mean (average) of the considered measurement in the 
interval, the calculated mean for the same measurement, and the 
absolute difference between the calculated and the observed 
means. Both the calculated and observed means are recorded 
to the nearest millimeter for length and to the nearest 0.1 cc. for 
volumes in these tables. 
3. Calculation of secondary tables. Secondary determinations 
made on the basis of the above calculations are included in tables 
2, 4, 5, 6, 10, 12, 14, 16. These include the absolute value of 
each measurement, as determined by calculation with the em- 
pirical formula, for each 5 em. of body length from 5 to 55 em., 
and the percentage and the absolute increment of these values 
for each 5-cm. interval between these points.! Included in these 
tables is also the ratio of the calculated value of the measurement 
at each 5 cm. of the total body length to the calculated value of 
the new-born. It was assumed that the value at 50 cm. of crown- 
heel length represented the new-born and the calculated values 
for the 5-cm. points below 50 are expressed in per cents of this 
one. The reduction of values to this common scale is of great 
convenience, since it permits their direct comparison regardless 
of their absolute magnitudes. 
4. Conversion of the various values from functions of the crown- 
heel length to functions of the age in fetal (lunar) months. This was 
done by calculating the values by means of the empirical formulae 
1The percentage increment was determined in the customary manner. The 
absolute value at the beginning of an interval is subtracted from the absolute 
value at the close of the same interval. The result is divided by the absolute 
value at the beginning of the interval and the quotient thus obtained is mul- 
tiplied by 100 in order to reduce it to a percentage basis. The percentage in- 
crement is the only simple form of expression of relative growth now in use which 
is at all satisfactory. However, it gives only a rough approximation of the actual 
rate of growth in a given interval. 
