MHMOIKS OF THE NATIONAL ACADEMY OF S("IKN('KS. 



177 



Oiip peculiar otlVct of tlio ociipihil llattfiiiiig is obsorvod in flic lioiizonlai ciicumferoiice. In 

 ciMtain ortlu'sf skulls (11. 1, II. 10. and II. J7) a turiou.s dilVuiilty has lici'ii encouiitcn-d concorniut,' 

 tlio liori/ontal ciicuinrcrenco. It is prescribed tluit this circunil(Meiue, which is su]ipiisd to lie th«i 

 maxiniuni, be taken on a line passing above the supraciliary ridffes and thion^'h the niaxiniuin 

 occipital point ; thus the posterior sejjnu'nt of the circuniferencc encircles, so to sjjcak, the jMj.sterior 

 end of the niaxiniuni len{;th. But in these skulls the line iudicatiiifj the greatest circuniferencc 

 pusses hijih up toward the obelion, and is drawn throufjh so high a plane of the .skull that the 

 greater breadth of the skull at points below that plane more than compensates for it.s slightly less 

 length ; therefore the maximum circumference does not lie iu the same plane as the maximum 

 length. 



Fio. 29.— Occipital depression, right lateral. 



Again; suppose that we take a skull of any ordinary shape and paint a line around it in the 

 horizontal plane of its greatest length. If we then look downward upon the vertex of the skull 

 we shall hardly see the line at all, because it corresponds so nearly to the outline of the skull in 

 norma virtivulis; but if we take one of the deformed skulls iu question and paint a line correspond- 

 ingly related to the maxinmm length and then look down npon the skull, we shall see painted 

 upon it an ovoid figure which coincides with the outline of the skull only at its posterior extremity. 

 This is owing to the fact that the most protuberant regions of the cranial parietes are situated 

 much below the horizontal plane of the greatest length. 



In these cases both the maximum circumference and the circumference around the maximum 

 occipital point have been recorded, although it has been a matter of great diilicMlty to determine 

 exactly the maximum circumference, and a series of measurements of the same made at long inter- 

 vals of time would i)robably show considerable variation. 

 S. Mis. IGO 12 



