THE SKULL THE CRANIUM 



301 



FIG. 220. 



downward and faces inward ; it then twists on its own axis so that the 

 inner surface faces upward and forward and is convex in both directions. 

 The fourth scroll (4') is nearly parallel with the third scroll, and is 

 wider behind, but at the middle of its length it becomes very narrow ; 

 at the anterior end it bends downward and backward, and, becoming 

 wider again, runs to the lower anterior angle, forming the anterior edge 

 of the surface; in this region it is usually split into two or three 

 smaller plates directed parallel with the anterior border. The fifth 

 scroll (4") has its shape and direction similar to the fourth, but it is 

 narrower in its horizontal portion and large and triangular in the 

 part bent in front down- 

 ward and backward ; this 

 larger part is wide above 

 and narrow below, and is 

 split into four delicate 

 leaves parallel with the 

 anterior border of the 

 surface. The sixth scroll 

 (5) is a very small spindle 

 occupying a deep position 

 between the posterior 

 ends of the fifth and 

 seventh. The seventh 

 scroll (6) is flattened 

 and triangular; the 

 truncated apex of the 

 triangle is on the lower 

 border. The posterior 

 inferior border runs 

 downward and forward, 

 parallel to the upper 



border of the eighth scroll, and close to it. The superior border is 

 slightly emarginate and runs straight forward or forward and slightly 

 upward. The anterior border is parallel to the anterior border of the 

 surface. This seventh scroll is marked by two or three curved vertical 

 or oblique grooves, of varying length and depth, which divide it into 

 several sections. The eighth scroll (7) is smaller, oval, and flattened. 

 The scrolls are attached to the cribriform plate behind. Their 



Palatine 



TRANSVERSE VERTICAL SECTION THROUGH HALF OF FACE. 



Three millimetres anterior to central part of cribriform plate of 

 ethmoid. Cut surfaces black (somewhat diagrammatic). 



