252 



HUMAN ANATOMY. 



or less up to 20. i centimetres. The scapular index is the ratio of the breadth, measured aiong 

 the base of the spine, to the length (^^n^^^^^)* -^^ ranges from 55 to 82. The following 

 means have been given for Caucasians : Broca, 65.9 ; Flower and Garson, 65.2 ; Dwight, 63.5. 

 A high index means a broad scapula, which is one of a low type. The mfraspinous mdex is 

 the ratio of the breadth to the length of the infraspinous fossa, measured from the lower angle 



to the starting-point of the spine ( inf r^p^nouTkngth ) ' ^^^'^ ^^r^z&s, from 72.3 to 100.2, with a 

 mean of about 87. Although high indices imply a broad scapula, this method is of small value, 

 as very diverse shapes may have similar indices. It is not possible to predicate anything of the 

 figure during life from the shape of this bone. The most that can be said is that a long arm 

 requires the leverage furnished by a long scapula. 



Differences due to Sex. — The chief point is the size. From the study of 

 eighty-four male and thirty-nine female bones it appearsthat of 123 bones, twenty-, 

 si.x measure less than fifteen centimetres in length, of which only three were male ; 

 also that seventy-six measure sixteen centimetres or more, of which only five were 



Fig. 271. 



ACROMION 



— Serratus magnus 



NECK 



Glenoid cavity 



Triceps [long 

 head) 



Subscap u la ris 



AXILLARY BORDER 



VERTEBRAL BORDER 



Ridges for tendi- 

 nous attach- 

 ments 



Process for ieies majot 



Serratus magnus 



Right scapula from before. 



INFERIOR ANGLE 



female. There was no single instance of a bone measuring less than fourteen centi- 

 metres being male, nor of one measuring seventeen centimetres being female. In 

 doubtful cases the glenoid cavity is very valuable. In woman it is not only smaller, 

 but relatively narrower. Very few male sockets are less than 3.6 centimetres in 

 length, and very few female as long. The typical female scapula is very delicate ; 



