511 



a) Normal Ill, 85.4 % 



Male 49 

 Female 62 



b) Auomalies in presacral region 3, 2.3 7o 



7 c, 13 t, 4 1, 5 s, 1 sCo, 4 Co == 34 (1 M., 1 F.) 



7 „ 13 „ 4 „ 6 „ 5 „ = 35 (1 F.) 



c) Anomalies in sacrum 1, 0.8 Vo 



7 c, 12 t, 5 1, 6 s, 5 Co, (1 F.) 



2) Columns with 23 presacral vertebrae .... 12, 9.2 7o 



Male 7 



Female 5 



7 c, 11 t, 5 1, 5 s, 1 sCo, 4 Co = 33 (1 F. ) 



7 „ 11 „ 1 tl, 4 „ 6 „ 3 „ = 32 (1 M.) 



7 „ 11 „ 0,6, 5 „ = 34 (1 M.) 



7 „ 11 „ 5 „ 5 „ 5 „ = 33 (1 F.) 



7 „ 11 „ 5 „ 5 „ 4 „ =32 (1 F.) 



7 „ 12 „ 4 „ 5 „ 4 „ = 32 (1 M.) 



1)7 „ 12 „ 3 „ 5 „ 5 „ = 32 (1 M.) 



7 „ 12 „ 4 „ 6 „ 4 „ = 33 (3 M. + 2 F.) 



3) Columns with 25 presacral vertebrae ... 3, 2.3 % 



Excess in lumbar region ; 

 7 c, 12 t, 6 1, 5 s, 4 Co. = 34 (2 M.) 



7 „ 12 „ 6 „ 5 „ 1 sCo, 3 „ = 34 (1 M.) 



The most noteworthy characteristic of spinal columns here tabu- 

 lated lies in the frequency with which reduction in the presacral region 

 is found, 12 instances, 9.2 °/o. In the bodies dissected in the labo- 

 ratory of the Johns Hopksins University this variation has likewise 

 been frequent. In a previous article in this Journal (1900) I pointed 

 out this fact and at the same time called attention to a reduction in 

 the size of the 12th rib, which often marks an anterior position of 

 the limb, judged by the limp plexus, even when the 24th vertebra has 

 not become converted into a sacral vertebra. I also pointed out that 

 the variations in the development of the distal margin of the thorax 

 are closely associated with the position of the ilium relative to the 

 spinal column. 



In the following table I have added an account of 11 vertebral 

 colums from the bodies in a room recently under my charge, to the 59 

 specimens previously reported. Of these 70 spinal colums, 16 (14 M., 

 2 F.) are from white subjects and 54 (34 M., 20 F.) from negro 

 subjects. 



1) Between Ig and s^ traces of incompletely developed vertebral 

 arches were found. 



