D. H. DE Souza 
505 
with the following results : 
Number 
Type of case 
D 
C (observed) 
C (calculated) 
1 
Achondroplasia 
7 
5-18 
2 
9 
7-14 
3 
Ateliosis 
9-21 
7-62 
7-3o 
» 
8-26 
7-62 
6-41 
5 
9-95 
8-07 
G 
>i 
8-5 
6-65 
7 
Rickety dwarf 
7 
6-25 
5-18 
8 
i> >> 
8-75 
6-90 
9 
Uncertain type 
8-47 
7-62 
6-62 
In No. 3 the calculated and measured values are very close, the former being 
slightly the less, but in 4, 7 and 9 the calculated value is about 1 cm. less than 
the observed value. In 4 the height of the hip bone was given, so that we were 
able to find the obstetric conjugate from the equation 
C = (D-1)-^H. 
The value obtained, 6"57, is a little nearer that of the observed value, 7'62, than 
is the value obtained from the diagonal conjugate alone, 6 "41. 
The last column shows that all the pelves are of such a degree of contraction 
as would call for special treatment during pregnancy or labour. The deformity 
would in most cases need no calculation to make it obvious. Even in extreme 
contraction, however, the formulae may be useful. In considering the advisability 
of Caesarian section in such cases, it is necessary to know whether the pelvis will 
admit the passage of even a dead child. This -can be readily ascertained by 
applying the formulae. The tendency seems to be for them to give too low 
values in these extreme cases. With the present-day results of Caesarian section 
this is to err on the safe side for both the mother and the child. 
Summary. 
1. Methods for obtaining the height of the hip bone on the living subject 
and for measuring the thickness of the tissues over different parts of this bone 
on the corpse, have been described. 
2. The averages and variability of the pelvic measurements have been found 
and the various measurements correlated. The obstetric and diagonal conju- 
gates show very high correlation. The inter-cristal is the diameter most closely 
correlated with the transverse diameter. Both the obstetric conjugate and the 
transverse diameter show good correlation with the height and breadth of the 
hip bone. Corresponding measurements on the two hip bones are more highly 
correlated than two measurements on the same bone. 
