20 Size of Articular Surfaces of Long Bones 



The purpose of this paper is to present a new method, which indeed 

 I have suggested before, but wliich I liad not established by a sufficient 

 series of observations; namely, the relatively small size of the articular 

 surfaces of the long bones in the female. If tliis be true it certainly 

 deserves a place among the laws of anthropology. While I Ijelieve that 

 this applies to the long bones in general, I have limited the demon- 

 stration of tlie principle to the heads of the humerus and femur. 



In the Shattuck lecture on the Range and Significance of Variation 

 in the Unman Sl-eleton, which I had the honor of giving before the 

 Massachusetts Medical Society in 1894 (3), I advanced the opinion that 

 the size of the articular surfaces of tlie limits has an important sexual sig- 

 nificance. I mentioned that I had studied the dimensions and propor- 

 tions of the glenoid cavity of the scapula on 63 male and 27 female 

 bones. Its average length in the male bones was 3.93 cm. and in those 

 of the female 3.36 cm. Very few male ones were less than 3.6 cm. and 

 very few female as long. Though I had made observations on the bones 

 of the arm and forearm I had no series large enough to quote; but I 

 spoke more in detail of the observations on 64 femora on which many 

 measurements had been taken, and which came from bodies that had 

 been measured before dissection. After discussing some of the more 

 common features as guides to determine the sex, I said : " Some other 

 measurements seem to throw more light on this matter. They tend 

 to establish the theory that the small size of joints is characteristic of 

 woman. They are the greatest diameter of the head of the femur and 

 the greatest transverse breadth through the condAdes. The average diam- 

 eter of the male head is 4.8 cm., that of the female 4.15. My tables 

 sliow one marked difference between the sexes; namely, that in the 

 women there is a fairly regular increase in the size of the head cor- 

 responding with the increase in length of the femur. Among men this 

 is not so. While it is true that most of the largest lieads are found in 

 the longer half of the bones and most of the smallest in the shorter half, 

 the correpondence is far less evident. I find, moreover, that but two male 

 heads have a diameter of less than 4.5 cm., and but two of the female a 

 greater. Both these female bones were among the longest, but the two 

 male were but little below the average. Thus it would seem that the 

 actual measurement of the head of the femur is a pretty good criterion 

 of the sex. The measurements of the knee are less conclusive. Tlie 

 average difference is just under one centimeter (8.3 and 7.3), but there 

 are more that overlap." 



Dr. Hepburn (4) published in 1896 measurements of femora of many 

 races, one of the measurements being that of the head. He did not, 



