Thomas D wight 37 



urements of 400 articular heads of humerus and as many of that of the 

 femur a scries of the length of 200 humeri and 200 femora, equally 

 divided between the sexes. The length of the thigh bone was taken by 

 the bicondylar method. The greatest possible length of the arm bones 

 was recorded. All the measurements were of bones of the right side. 

 It is very evident that the difference between the bones of the arm and 

 thigh in the matter of length are much less important sexually than those 

 of the diameters of the heads. In comparing the curves (Plates IV and 

 V) it is to be remembered that the observation of the lengths are but 

 half as numerous as those of the joints. 



The average length of the male humerus is 32.46 cm., that of the 

 female 29.98 cm., which is 92.36 per cent of that of the male. The 

 average male femur measures 44.95 cm., the female 41.55 cm., or 92.44 

 per cent of the former. The diameter of the head of the female femur 

 approaches that of the male rather more closely than either of the 

 diameters of the head of the humerus, yet its percentage is only 88.24, 

 Before plotting the curves, the millimeters were suppressed, each bone 

 being recorded as at the nearest centiraeter. Cases which came at pre- 

 cisel}^ half a centimeter were put at the lower mark. 



I pointed out in the case of the joints how very few male ones were 

 below the female average, and how very few female ones above the male 

 average. It is easy to see by consulting the curves of the lengths, in 

 which the averages have been marked, that though there are only half 

 as man}^ observations there are, especially in the case of the female 

 femora, decidedly more beyond the line. The contrasts between the two 

 sets of series when divided into a smaller and a larger half are very 

 instructive. Let us take first the length of the humerus. If the dividing 

 line be put between 31 and 32 cm., we find 119 in the first division 

 and 81 in the second. In the former there are 22 male and 23 female 

 bones measuring 31 cm. If we transfer 9 males and 10 females (9.5 

 per cent of the whole) we have 100 in each division. There are 24 males 

 in the shorter 100 and 24 females in the longer 100, i. e., 24 per cent of 

 each sex in the wrong half. If we draw the dividing line for the femora 

 between 43 and 44 cm., we have 118 in the shorter division and 82 in the 

 longer. There are 16 male and 16 female bones measuring 43 cm. If 

 we transfer 9 of the former and 9 of the latter (9 per cent) to the longer 

 division we again have two divisions of 100. Among the shorter 100 are 

 27 (27 per cent) male, and among the longer 27 female (27 per cent). 

 A glance at the former statement of this manipulation with the diameters 

 of the joints will show that the percentage of specimens transferred was 

 insignificant, never over 2.25 per cent, and the result much better. 



