REPORT ON THE BONES OF THE HUMAN SKELETON. 
67 
evident that, whilst in the 1st and 2nd lumbar vertebrae the body was deeper behind 
than in front in a considerable proportion of the specimens, in the 3rd and 4th lumbar 
the reverse occurred, until in the 5th lumbar the bodies of all the specimens had a 
greater vertical diameter anteriorly than posteriorly, and this indeed is a character of the 
5th lumbar that has long been recognised by the descriptive human anatomist. The 
vertical diameter of the body of the 4th lumbar in the twelve skeletons amounted to 
336 mm. for the anterior surfaces collectively, and to 313 mm. for the posterior surfaces 
collectively. In the 5th lumbar the vertical diameter of the anterior surfaces collectively 
amounted to 337 mm., and the posterior surfaces to 281 mm.; the mean anterior depth 
was 28 mm., the mean posterior 23'4, and the mean difference in favour of the anterior 
surface was 4 ’6 mm. Hence it follows that of all the lumbar vertebrae the 5th had much 
the greater proportional depth at the front as compared with the back of its body, and 
that it contributed more than any of the others to the anterior convexity of the lumbar 
region, so far as that is produced by the bodies of these vertebrae. 
For the purposes of comparison of the lumbar region in Europeans with the same 
region in the spines of other races of men, it may be well to frame a general lumbar index 
for the entire region, and a special index for the body of each vertebra. If we assume the 
vertical diameter of the bodies of the five vertebrae anteriorly to be = 100, then the formula 
posterior ^ diameter x 100 wou pj - e +} ie g enera l lumbar index , and by a similar formula 
the anterior diameter 
the special index of each vertebra may be obtained. 
In Table X. the mean index of each lumbar vertebra in the series of twelve European 
spines is given, from which it will be seen that the index diminished from 106 '8, that of 
the 1st lumbar vertebra, to 83'6, that of the 5th. The mean general index of the series 
of five lumbar vertebrae was 96. Dr. Cunningham in the abstract of his researches on 
Table X. — Lumbar Indices. 
Mean special Index of 
1 2 Europeans. 
5 Australians 
(4 ? , 1 6 )• 
2 Andaman 
Islanders. 
3 Negros 
(2 9, 1 P). 
3 Oahuans, 
Sandwich 
Islands. 
1st Lumbar vertebra, 
106-8 
114-4 
111-3 
108-8 
114-6 
2nd „ „ • 
101-5 
112-3 
105-6 
104-2 
108-0 
3rd j? ?3 • 
95-4 
108-0 
102-0 
100-0 
108-2 
4th „ „ . . 
93-0 
103-7 
91-8 
93-0 
101*5 
5th „ „ . . 
83-6 
91-4 
84-2 
89-0 
87-7 
Mean general Lumbar Index, 
960 
105-96 
— 106 - 0 
98-98 
= 99-0 
99-0 . 
104-0 
