cv.3 J ev/ 



m -W.6V 



Fig. 2. Photographs of Six Pairs of Scapulae from White Males in the Age Period 

 Sixty to Sixty-nine, Derived from Dissecting-room Material, Laboratory of 



Anatomy, Western Reserve University Medical School, Cleveland, Ohio 

 The three pairs on the left (Convex, Straight and Concave types) in the order named 

 from top to bottom are typical "pure" types, i.e., each bone of each pair is of the same 

 type. The three pairs on the right are "mixed" (scaphoid) types (Concave + Convex, 

 Straight + Convex, Concave + Straight) in the order named from top to bottom. In 

 classifying relatively large numbers of paired scapulae of skeletal and living material, 

 80 to 90 per cent are found to be similar in type, both being convex, straight or concave, 

 although one frequently finds marked differences in degree of convexness and concaveness. 

 In paired scapulae, 10 to 20 per cent of such are found to be dissimilar types, i.e., 10 to 15 

 per cent are convex on one side and straight on the other; 3 to 5 per cent straight on one 

 side and concave on the other; and 1 to 2 per cent convex on one side and concave on the 

 other. Dissimilar types (Cv + St, St + Cc, Cv + Cc) are called mixed (scaphoid) types 

 for the reasons : (1) mixed types have scaphoid components; (2) the general characteristics 

 of the bearers of mixed (scaphoid) types are often similar to those of the bearers of the 

 straight and concave (scaphoid) types; and (3) the age incidence of mixed (scaphoid) types 

 is similar to that of straight and concave (scaphoid) types, as indicated in tables 1 and 2; 

 therefore classification of paired scapulae is as follows: 



In paired scapulae, differences in degree of convexness or concaveness and dissimilarity 

 in types are independent of sex, handedness and occupation or environmental influences. 



459 



