22 Size of Articular Surfaces of Long Bones 



fresh. This is certainly proper for tlie })urpose of an anthropological 

 study as it represents the size of the joints as they are in life. Moreover, 

 on many dried bones, the cartilage remains as a very thin layer, which, 

 though amounting to little, causes a discrepancy between those bones 

 and others in which it has been quite removed. The question of what 

 deduction from diameters thus obtained should be made in comparing 

 them with those from dry bones shall be considered later. 



When I had obtained these measurements on 100 male and 100 female 

 bones I tabulated the results and drew the curves. While the results 

 seemed to establish the law, the curves were so irregular that it seemed 

 certain that they could hardly show a true mean. I then made 50 more 

 examinations in each sex, and again was dissatisfied with the curves, 

 and undertook 50 more. Thus I have now the measurements of 400 

 bones equally divided between the sexes. Owing to the relative scarcity 

 of female subjects, I think the additional hundred measurements of 

 female bones has retarded me by nearly three years. The bones were 

 those of white adults, and in every case the humerus and femur were 

 both measured, so that comparisons can be made between the upper and 

 lower extremity. It was not possible to restrict the measurements to 

 bones of one side, as post-mortem injury or some pathological blemish 

 often rendered at least one of the joints unavailable. They seem to 

 establish the point at issue. 



The averages are as follows : 



Head of Humerus. Head of Femur. 

 Vertical. Transverse. 



Male 48.7(> mm. 44.66 mm. 49.68 mm. 



Female 42.67 " 38.98 " 43.84 " 



Difference 6.09 mm. 5.68 mm. .5.84 mm. 



The above average measurements of the female are to the respective 

 male ones as 87.51, 87.28 ; and 88.24 are to 100. (Plates I, II and III.) 



It is easy to see by the curves (Plates I, II and III) that there is only 1 

 male with a vertical diameter of the head of the liumerus below tliat of 

 the average female, and only 2 females with the same diameter above 

 that of the average male. Taking the transverse diameter of the head 

 of the humerus we find 2 males below the female average, and 3 females 

 above the male average. With the head of the femur we have but 1 male 

 below the female average and but 1 female above the male average. 



Taking separately the three series, each of 400 measurements, the fol- 

 lowing deductions may be made : 



