'JMiomas I)\viol)t 21 



however, make any attempt to consider the sexual significance of the head. 

 In fact, there were but few -females among the bodies of Europeans from 

 which the bones were taken. He mentions, however, incidentall}', tluxt 

 the diameter of the head of the male femur was never below 40 mm., 

 except among the Andamans; and also that a diameter below 40 was 

 found in several female bones of various races. 



Dr. Dorsey (5) published in 1897 a paper recording observations on the 

 long bones of American aborigines in which he tested tlie accuracy of 

 my views, taking the greatest diameter of the head of tbo liiimcrus and 

 of the femur and also the breadth of the upper end of the tibia. The 

 sex was first decided from the pelvis. His results from the heads of 

 the bones of 135 skeletons of various races of Ijotli Nortli and South 

 America were very strikingly in confiiination of the value of the size of 

 the joints as a sexual characteristic. " Thus, if the maximum diameter 

 of the head of the humerus of any American skeleton measure 44 mm., 

 the chances are extremely great that it is a male; if it measure 45 mm., 

 it is a male to a practical certainty. The inference to be drawn from the 

 measurements of the femur seem almost, if not quite, equally valuable; 

 and it would almost seem that we could determine the sex from the femur 

 alone with a great deal more certainty than we could from the skull. 

 After Professor Dwight's disparaging remarks about his results from 

 measurements through the condyles of the femur, I was quite unpre- 

 pared for the results which have been derived from the tibia. The range 

 of variation is, to be sure, greater than it is for either the humerus 

 or the femur; and this, it may be repeated, is largely due to the discrep- 

 ancy in stature between the North and South American skeletons, but 

 the dividing line for the two sexes, between 71 mm. and 72 mm., is almost 

 as sharp as it is for the femur, and makes the tibia a valuable aid for the 

 determination of sex,'' 



Although I was satisfied that the principle that the small size of joints 

 is characteristic of woman is correct, I felt that it should be established 

 by a series of measurements large enough to be beyond question. Accord- 

 ingly, I undertook to make the measurements of the head of one humerus 

 and one femur of 100 male and as many female bodies. Those of white 

 adults only were used. The head of the humerus was measured in both 

 the vertical and the transverse diameter, the object being to get the great- 

 est diameter for each, even if it deviated somewhat from the strictly verti- 

 cal or transverse plane. In the femur the greatest possible diameter was 

 carefully sought for. The measurements were made with blunt calipers. 

 The bodies were those used for anatomy and surgery in the Harvard 

 Medical School. I took the measurements when the cartilage was still 



