THE HUMAN STERNUM 37 



The breadth index ( '°°^ — j of the male presternum is i25'5 ; of the 



female presternum is I23'2. The length index \ °^ ) of the male pre- 

 sternum is 79'6 ; that of the female presternum, 8i*i. The male pre- 

 sternum, is, therefore, wider and shorter ; the female, longer and 

 narrower. 



2. Mesosternum. 



The average measurements (Table XII) of the mesosternum are : — 



Length Breath 



Male 103-7 n^™- • 4°"5 '^"^• 



Female 91-0 mm. . 36-8 mm. 

 The indices for the two sexes are : — 



Length index Breadth index 



Male 256 . 39 



Female 247 . 40*4 



The male mesosternum is, therefore, on the average, longer and narrower ; 

 the female shorter and broader. 



The statistical method does not very clearly indicate a point that was 

 often obvious in the examination of the series. In the female, the meso- 

 sternum is often extremely broad in the lower part (PI. VI, Fig. 42A), so as 

 to give rise to a ' type ' of sternum which can be almost designated the 

 ' female ' type ; although it must be admitted that this type is not unfrequently 

 found in male sterna as well (PI. VI, Fig. 42b). 



3. Metasternum 



The measurements of the metasternum are vitiated because of the 

 dry and shrivelled condition of this part of the bone. However, as all 

 measurements have been taken in the same way, they are included for what 

 they may be worth. The measurements are : — 



Length Breadth 



Male 40-0 . 20-0 

 Female 33-5 . i6'o 



The indices are : — 



Length index Breadth index 



Male 200-0 . 50-0 

 Female 209-3 . 47*7 



