NO. I THE HYPOTROCHANTERIC FOSSA HRDLICKA 35 



Another feature that since Houze's initial report has been believed 

 by many to stand in correlation with the fossa is platymery, and the 

 concomitant lipping of the lateral border, of the subtrochanteric part 

 of the femur. Pearson and Bell, who tested the matter mathematically, 

 found (p. 79) that there was only " a small but just sensible correla- 

 tion between platymery and the presence of the fossa ". How small 

 the correlation is may be seen from the two columns below : 



THE FOSSA AND PLATYMERY 



Our nine racial groups arranged on Same nine racial groups arranged 



a basis of platymery, from its on the basis of incidence and 



maximum (lowest index) to its development of hypotrochanteric 



minimum (highest index) : fossa, from highest to lowest : 



Old Peruvians Aleuts 



Aleuts Eskimos 



N. A. Indians Old Egyptians 



Pre-Aleut Kodiaks N. A. Indians 



Eskimos Pre-Aleut Kodiaks 



Old Egyptians U. S. Negroes 



Chinese U. S. Whites 



U. S. Whites Old Peruvians 



U. S. Negroes Chinese 



The first column is probably not absolutely stable. Larger num- 

 bers of specimens in such groups as the Aleuts, Kodiaks, Chinese, 

 and Negroes, or the addition of a sufficient number of females to the 

 latter two groups, which include males only, might change the exact 

 position in the row of some or even all of them, but such changes 

 would in all likelihood be small. They would not substantially alter 

 the obvious fact that there can at best be but little correlation between 

 the two features in question. 



Nor are these the only facts that speak against such an interde- 

 pendence of the fossa and platymery, and also between the fossa and 

 the lip of the lateral border. There are highly platymeric and lipped 

 femora with but moderate or small fossae, and there are large fossae 

 with but moderate platymery lipping. And the conditions in the 

 anthropoid apes, so far as they apply to the question, do certainly 

 not testify for any clear correlation. 



In view of all this, in the rare cases where a pronounced fossa co- 

 exists with marked platymery and lipping, it seems legitimate to 

 doubt their causal connection. These considerations, however, con- 

 nect directly with the subject of the etiology of the fossa, a detailed 

 discussion of which will be left for another paper. 



