1868.] 



445 



[Wyman. 



in the Negro, and liis statement has been quite generally repeated by 

 subsequent writers. Frichard, however, satisfied himself that such 

 is not the ease, and after having examined i'many Negro skulls," 

 states that the foramen eorresponds in position with that of the white 

 races, viz.: "exactly behind the middle of the antero-jiosterior diam- 

 eter of the basis cranii."* He, however, finds it necessary, in order 

 that this should be the case, to make some allowance for the projection 

 of the jaws. We have seen no account of the manner in which the 

 measurements on which this opinion rests wei-e made, except that the 

 jaws were included when the antero-posterior diameter of the head is 

 spoken of. It is obvious that in comparing more or less prognathous 

 races, the position of the foramen magnum may be found to vary, 

 although there may be no variation when the cranium proper is alone 

 considered. In other words, the bones of the face may vary inde- 

 pendently of the cranium. 



The more common method adopted has been to measure from the 

 anterior edge of the foramen magnum to the edge of the alveoli 

 in the middle of the upper jaw, and from the foi-amen to the most 

 prominent pomt of the occiput. It seems to us more correct to 

 determine the position of the foramen, with regard to the cranium, 

 than with regard to the cranium and face, especially as the chief in- 

 terest which attaches to the foramen is as an index of the relation of 

 the spinal marrow to the cerebral mass. 



Fig. 1. 



In making the measurements on which the following table is based, 

 we have kept this circumstance in view, and have adopted the follow- 

 ing method. The cranium is placed inverted in the instrument repre- 

 sented in the accompanying figure (Fig. 1.) the long diameter, 



■ * Researches into the Physical History of Mau. London, 1851. Vol. i., p. 285. 



