NO. I 



THE liyPOTROCHANTEKIC FOSSA — HRDLICKA 



29 



111 the main the conditions are much like those in the previous 

 groups, the only exception being that one of the rather pronounced 

 fossae in an older child is a groove. There is also a sensible propor- 

 tion of fossa-grooves in both the adolescent groups. In the older 

 adolescents, it may be noted, the fossa is again almost universal, and 

 in nearly 40 percent — practically the same as in the Egyptians — it is 

 above medium to pronounced in development. 



NORTH AMliRICAN INDIANS 



This group includes tribes from many parts of the continent, and 

 the bones range from pre-Columbian (the majority) to fairly recent 

 but probably free from white admixture. The number of juvenile 

 femora in this group is very respectable, reaching a total of 626 

 specimens, and ranging from preterm to subadult. There were no 

 indications of any material tribal or regional differences, and so all 

 the data may be dealt with as a unit. The conditions it shows are 

 as follows : 



Hypotrochanteric Fossa in North American Indians, Children and Adolescents 



No. of femora 



Younger children 

 (to approx. 6 

 years) (283) 



Older children 

 (approx. 7 to 13 

 years) (64) 



Younger adolescents 



(117) 



Older adolescents 



(162) 



Percent Percent 



34 6 



15 6 

 3-4 



2.5 



24.7 



7.8 



4 3 

 1 .2 



Small 



but 



distinct 



Percent 



23-7 



21 .9 



12- 



19 



Mod- 

 erate 



Percent 

 10.3 



26.6 



16.7 



Medium 



Percent 

 6.4 



25- 

 29. I 

 40.7 



Above 

 medium 



Percent 

 0.4 



31 



22 .2 

 27.2 



Pro- 

 nounced 



10.3 

 9-9 



Of 



which 



fossa- 

 groove 



Percent 



(0.7) 



(4-7) 



(3-4) 



(II. I) 



The above results conform with those seen in the other groups 

 of femora. As age advances, during the growth period, the " none ", 

 with the " trace " and " small " grades of the fossa, diminish, the 

 " medium " to " pronounced " increase. From birth to later adoles- 

 cence there is a steady and marked increase in the incidence of the 

 fossa, with a progressive marked diminution in its " trace " and 

 " small " grades, together with an equally progressive and marked 

 increase in large fossae. The " above-medium " to " pronounced " 



