58 THE SUTURES. 



ossification, in one or more points ; from which the ossification 

 is extended to form as many distinct bones as there were points 

 which are extended into the large ordinary bones, and into 

 each other.* 



The sagittal suture is placed longitudinally, in the middle 

 of the upper part of the skull, and commonly terminates at 

 the middle of the coronal and of the lambdoidal sutures ; 

 between which it is said to be.placed, as an arrow is between 

 the string and the bow. This suture is sometimes continued 

 through the middle of the os fronds down to the root of the 

 nose. * 



The squamous agglutinations, or false sutures, are one on 

 each side, a little above the ear, of a semicircular figure, formed 

 by the overlapping (like one scale upon another) of the upper 

 part of the temporal bones on the lower part of the parietal, 

 where, in both bones, there are a great many small risings, and 

 furrows which are indented into each other : though these 

 inequalities do not appear until the bones are separated. In 

 some skulls, indeed, the indentations here are as conspicuous 

 externally as in other sutures ; and what is commonly called 

 the posterior part of this squamous suture, always has the 

 evident serrated form ; and therefore is reckoned by some a 

 distinct suture, under the name of additamentum posterius 

 suturae squamosae. 



The squamous suture is not confined to the conjunction of 

 the temporal and parietal bones, but is made use of to join all 

 the edges of the bones on which each temporal muscle is 

 placed ; for the two parts of the.sphenoidal suture, which are 

 continued from the anterior end of the common squamous 

 suture just now described, one of which runs perpendicularly 

 downwards, and the other horizontally forwards ; and also the 

 lower part of the coronal suture already taken notice of, may all 

 be justly said to pertain to the squamous suture. 



* These ossa triquetra or wormiana are also frequently met with in the sagittal 

 suture, and occasionally in all the different sutures of the cranium. As many 

 as fifteen or twenty have been seen in a single head, though usually their num- 

 ber is much less. Where the cranium is of a globular form, few, and frequently 

 none, are met with. They never begin to ossify till six months or a year after 

 birth. P. 



