NO. I THK HYF0TR(J(:11ANTER1C KOSSA HKULICKA 4^ 



The sex differences in the incidence and development of the hypo- 

 trochanteric fossa on the whole are, it is seen, rather insignificant. The 

 males have a slight excess of the large fossae and also of the fossa- 

 grooves, but in the American Indians, both North American and of 

 old Peru, it is the females that predominate slightly in this respect, 

 as they do also in the total frequency of the fossa. 



More in detail, the Indians, both North American and those of 

 Peru, stand somewhat apart in this respect from the rest of the groups. 

 They show a larger proportion of the " absent " and " trace " in the 

 males, with a slightly larger proportion of the " pronounced " forms 

 and of the fossa-groove in the females. The females here in this 

 respect, as in so many others, show more juvenile character. In the 

 rest of the groups, except the Negroes, where the numbers are in- 

 sufficient, the " absent " are nearly alike in the two sexes, the " trace " 

 to "above medium" grades differ moderately and irregularly, and 

 the " pronounced " forms of the fossa and the fossa-grooves, equal in 

 the two sexes in the Whites, predominate in the males in the Egyptians 

 and the Eskimos. 



The conclusion of Von Torok, Evangeli-Tramond, and Pearson and 

 Bell, that the fossa was more frequent in the males, is thus subject 

 to corrections. The important age factor, it may be said, is presumably 

 much alike in the two Indian and the Eskimo series, but dift'ers in 

 the rest, which doubtless has had some effect on the records. 



DIFFERENCES IN ADULTS AS TO SIDE 



The large adult series of human femora at our disposal make it 

 possible to learn something definite on the diff'erences in the incidence 

 and development of the hypotrochanteric fossa on the two sides of 

 the body. Pearson and Bell's results on this point were, it will be 

 recalled, contradictory, and nothing decisive was observed in this 

 respect on our North American Indian juveniles. The data, to start 

 with, may most conveniently be presented without regard to sex. A 

 very large proportion of the femora involved in the study are paired. 



Some appreciable side diff'erences evidently exist, but they are not 

 large. On the whole, the rights show more " absent " and " trace " — 

 meaning probably more obliteration; somewhat less of "small" to 

 " medium " ; about the same of the " pronounced " ; and rather notably 

 more of the fossa-grooves. Group differences are small except in the 

 old Egyptians, where the right bones show decidedly more on one 

 hand of the " absent " and " trace " and on the other of the "above 

 medium " and " pronounced," as well as a much larger proportion of 

 the fossa-grooves. 



