MHMOIKS OF THE NATIONAL ACADEMY OF SCIENCES. 211 



hi a soncs of .!(! iu>',Mi >os ihv in'.ipiiitioii of the depth to tlio width is 65 por cent and a fraotioK, 

 or bi'twi'oii 11 and IJ |hm cint nioro simian. In one case (Fig. 42) the proportion goes aa high aa 

 90 per cent, while 75 per cent is not at all uniisinil in the series. 



In the few specimens of the white liyoids which we have the proportion aeeins to be abont 50 

 per cent, itlthough wc liave not been ai)le to determine this with any degree oi" exactness. (See 

 Fig. 43.) 



Fio. 42 Anterior and Posterior vicwn of negro hyoid. 



In conclnsion we will say that in the present state of our knowledge it is well-nigh impossible 

 to give any intelligent exjjlanation of the facts which have been set forth above, with the possible 

 exception that the greater basihyal index of the Negro is to be accounted for on the l)asis ot his 

 nearer relationship to the monkey. Regarding the coossilication of the greater cornua with the 

 body little can be said, but it might be suggested that, siuce the chief function of the hyoideau appa- 



terior views iif European liyoid. 



ratus is the support of the muscles of the tongue, one would be led to infer that it has Something to 

 do with language. It is supposable that in those races where rapid talking and much talking was 

 the rule the hyoidean elements would coossify early, while among those people who s])eak slowly, 

 deliberately, and comparatively little, the hyoideau elements would unite late in life, if at all. The 

 complexity and modification of sounds depending largely upon the use of the tongue would also 

 furnish sutHcient reasons for early or late coos.siflcation. 



i 28. INDICES OF THE LONG BONES. 



The indices of the long bon«s (Table Li) which have been taken are the antibrachial and the 

 tibiofemoral. The measurements from which these were computed have been taken by means of 

 tlm j'lanchc osteomctriqvc in use in France and according to the directions given by Topinard.* 

 These directions require that all the bones except the tibia shall be so measured as to obtain their 

 maximum length. The tibia is measured from the superior articular surface to the internal mal- 

 leolus; thus the length of the intercondylar spine for the insertion of the cruciform ligaments is 

 subtracted. The measurements have been taken with great care and are correct to a millimeter. 



The indices are reckoned by means of the following formuhe : For the antibrachial index the 

 length of the radius is multiplied by 100 and the product divided by the length of the humerus; 

 for the tibiofemoral the length of the tibia is multiplied by 100 and the product is divided by the 

 length of the femur. 



Very few of the skeletons have complete sets of long bones. In many cases only one remains 

 whole. Therefore, in order to obtain the greatest possible results, we have adopted the following 

 plan : 



Method I. "We compute the indices from bones belonging to the same limb of the same skeleton. 



•TOPINARD, op. cit., p. 1033. 



