70 THE TONER LECTUEES. 



THE GROOVES, OR THE INFLUENCES EXERTED BY BLOOD- 

 VESSELS IN DETERMINING THE FORM OF THE SKULL. 



Inspection of the bones of the human subject sliows that the sur- 

 faces are not infrequently marked by superficial grooves which 

 appear to be the tracks of blood-vessels. Such markings are best 

 seen in the long bones, which exhibit the usual appearances of 

 chronic inflammation. Assuming that the impression made upon 

 the bones are'proportionate to the amount of increase of volume of 

 the bone, and that the vessels remain fixed, a simple problem is 

 presented by means of which the observer can determine the signifi- 

 cance of blood-vessel tracks in other than in inflammatory conditions. 



The vessel-grooves on the periphery. — The cranium yields a num- 

 ber of examples of these grooves. In the forehead, especially of 

 specimens in which the forehead is rounded, numbers of deep, 

 narrow grooves an inch or more in length are seen extending up- 

 ward and backward from near the supra-orbital foramen or from the 

 outer side of the frontal eminence and in line with the supra-orbital 

 foramen or supra-orbital notch. In rare instances a simple small- 

 groove lies near the frontal portion of the temporal ridge.^ I have 

 seen both the above-named grooves present in a child of nine months 

 of age. They appear earlier than the grooves described in the suc- 

 ceeding paragraphs. 



Good examples of the frontal vessel-grooves have been found in 

 skulls of all nationalities. They are not uncommon in the negro, 

 when the narrow, convex forehead appears to favor their appear- 

 ance.^ 



1 See No. 760, Copt, for a good example and many negro crania. 



2 For example see: Nos. 905, 912, negro; No. 438, Ohio Indian; No. 

 1035, Apache; No. 87, Peruvian; No. 1024, Fiji; No. 1214, Hamilton, 

 Ohio, Indian; No. 1043, Pawnee; Nos. 78, 44, 35, 1222, Menominee; 

 Nos. 749, 650, Minitari ; Nos. 744, 745, Blackfoot ; No. 1057, Miami ; 

 Nos. 644, 742, Mandan ; Nos. 39, 1333, 1233, unnamed. 



