446 
HALBERT L. DUNN 
The percentage increment of the pons length against intervals 
of growth in body length (fig. 25, curve V) starts at 30 per cent 
between 10 and 15 cm. (C H) and falls steadily but slowly to 
9.8 per cent in the 50-to-55-cm. interval. 
The percentage increment of the pons length as calculated for 
fetal months (fig. 27, curve III) shows a rate of growth of about 
TABLE 25 
Pons length 
Formula: Pons length (em.) = 0.0263 crown-heel length (cm.) + 0.16 
(124 cases) 
CROWN-HEEL LENGTH OBSERVED PONS LENGTH eae 
— Cau EAE GHSEe RAND NUMBER 
Range Mean Sa Nips ae te x cas air oe ie GIP eaters 
cm, cm, cm. cm. cm, cm, cm. 
Oto 5 
5 to 10 
10 to 15 UPA 0.6 0.3 0.5 0.5 0 18 
15 to 20 16.7 0.8 On5 0.6 0.6 0 13 
20 to 25 22.6 0.9 0.7 0.8 0.8 0 18 
25 to 30 27.0 TA 0.6 0.9 0.9 0 13 
30 to 35 32.8 its 0.9 1.0 10) 0 16 
30 to 40 Sieik i) 1.0 lig? ipa =e 18 
40 to 45 42.2 1.4 1.0 es 1,333 0 12 
45 to 50 48.2 ie 11824 1fa8ts) 1.4 —0.05 8 
50 to 55 52.2 176 eS 15) 125 0 8 
TABLE 26 
Calculated pons length at 5-cm. intervals of crown-heel length 
CROWN-HEEL LENGTH 
PONS LENGTH 
INCREMENT IN EACH 
5-CM. INTERVAL 
ee 
29 
55 
68 
81 
94 
.08 
21 
34 
47 
60 
p 
~) 
Peer OOOCOCo 
cm. 
plas 
alec 
PRE 
.13-++ 
“BSS 
si BSE 
.13+- 
sllsse 
.13+ 
0.13+ 
SSeS} (See) 
per cent 
RATIO TO NEW-BORN 
per cent 
28.7 
37.6 
46.5 
50.4 
64.3 
73.3 
82.3 
91.2 
100.0 
108.8 
