MEMOIES OF THE NATIONAL ACADEMY OF SCIENCES. 



211 



In a series of 36 negroes the proportion of the depth to the width is 65 per cent and a fraction, 

 or between 11 and 12 per cent more simian. In one case (Fig. 42) the proportion goes as high as 

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



In the few specimens of the white hyoids which we have the proportion seems to be about 50 

 per cent, although we have not been able to determine this with any degree of exactness. (See 

 Fig. 43.) 



Flo. 42 Anterior and Posterior views of negro hyoid. 



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

 to give any intelligent explanation 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 basis of his 

 nearer relationship to the monkey. Eegarding the coossification of the greater cornua with the 

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



Fio. 43. Anterior and Posterior views of European hyoid. 



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 speak slowly, 

 deliberately, and comparatively little, the hyoidean 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 sufficient reasons for early or late coossification. 



$ 28. INDICES OF THE LONG BONES. 



The indices of the long bones (Table LI) which have been taken are the antibrachial and the 

 tibio-femoral. The measurements from which these were computed have been taken by means of 

 the planche osteometrique 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 formula? : 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 tibio-femoral 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 

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

 plan: 



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



TOPINARD, op. tit., p. 1033. 



