52 THE TONER LECTURES. 



ration and may be deflected from the line of the intertuberal por- 

 tion. It corresponds nearly to the position of a depression which 

 is commonly symmetrical on either side of the suture as seen on the 

 cndocranial surface. When well marked it may receive the name 

 of the post-bregmal portion. In Negroes it is commonly merged in 

 the intertuberal. 



The third portion of the sagittal suture is the obelion of Broca.' 

 The parietal foramina lie on the sides and serve as guides to this 

 the obellal portion. 



Broca describes the obelion as having a length of 2'^, measuring, 

 as it does, 1" either way from the foramina. The suture is very 

 commonly harmonic, while it may be sinuate, serrate,'^ or lobate, but 

 rarely the last named. The vertex, as a rule, is rounded or ridged 

 at the sides of the obelion, which thus appears to be depressed. 



The fourth and last portion of the sagittal suture also appears 

 to be depressed. It extends from the obelial to the larabdoidal sut- 

 ure. The serrations are coarse, and are often composed of denti- 

 cles which exceed in length any seen in the foregoing divisions of 

 the sagittal suture. In the growing subject it is often the thickest 

 part of the suture. It measures from 1 to 2 centimeti-es in length 

 and may be called the post-obelial portion. 



The coronal suture is constantly divided into three parts — the in- 

 ternal or ental, which answers to the anterior fontanel ; the mid- 

 dle or mesal, and the external or ectal. The internal is simple or 

 wavy ; the middle is denticulate and extends from the internal third 

 to the stephanion, while the external or ectal is again simple, and lies 

 between the stephanion and the pterion. It is covered by the tem- 

 poral muscle. The external or ectal may remain open while the 

 remaining portion of the suture is obliterated (No. 38, Col. of 

 Phys.). In some subjects, notably the Negro, the middle portion 



1 Instructions Craniologiques et Cmnioraetriques, Paris, 1875, p. 24. 



2 Out of the 55 crania of negroes in the collection of the Academy of Nat- 

 ural Sciences 35 exhibited sinuate obelial portions and 20 serrate. 



