170 



ME. BTJSK ON YEDDAH SKULLS. 



of the skull, as may be seen in Tig. 2, where the outer square 

 lines may be taken to represent the stem and branches of the 

 craniometer, the radius sought being the distance between the 

 lines o o and a a. These radial measurements will be taken in 

 the same directions as the transverse arcs just described, and are 

 termed respectively — 



12. The frontal radius. 13. The vertical radius. 



14. The parietal „ 15. The occipital „ 



The longitudinal dimensions of the regions are estimated by a 

 graduated tape, stretched from the fronto-nasal suture to the pos- 

 terior margin of the foramen magnum, the distance being sub- 

 divided into, 



16. The frontal longitudinal arc, terminating at the coronal 

 suture. 



17. The parietal longitudinal arc, corresponding in length to 

 the sagittal suture ; and 



18. The occipital longitudinal arc, or the distance from the 

 same point to the foramen magnum : and on this may be marked 

 out the position of the occipital spine. 



19. The circumference is measured by a graduated tape carried 

 round the head immediately above the frontal sinuses or super- 

 ciliary eminences, where they exist, or in the direction indicated 

 by the dotted line c c, fig. 1. 



These are the measurements relating more especially to the 

 cranium regarded as a whole, and its regions, upon which the com- 

 parisons above given of the different crania are founded ; but those 

 relating to the face may also be briefly noticed. They are, 



20. The zygomatic width, or that between the zygomatic arches 

 0, fig. 3). 



21. The orbital width, measured between the external orbital 



processes. 



22. The ethmoidal, or the width of the ethmoid bone between 

 the orbits. 



T-). The nasal or fronto-nasal radius (n, fig. 1), corresponding 

 pretty nearly to the cranial axis of Prof. v. Baer, though not to 

 the true cranial axis, which can scarcely be measured unless the 

 skull is bisected. 



21. The maxillary radius (m, W^. I ),- - the dillerenco between 

 the last two indicating the degree of ortho- or prognathism, per- 

 haps more precisely than the so-termed facial angle. 



