208 



DETAILED SYNTHESIS. 

 FIG. 160. 



bottom of the front part, and two thirds down the back part, and down 

 tbe centre to the arched line shown, under which connections between the 

 right and left brains stretch across. 



Thus the Cranium is divided into its right and left cavity. Into the 

 right one the eye looks and sees 39 and 35, on the inner surface of the right 

 wall of the Cranium. From the form of the partition, 36, it is called the 

 FALX or sickle. From its lower edge it extends back again up to the cra- 

 nium, joining it near where it left it, but, spreading a little, it leaves a 

 triangular space, 38, that properly lined becomes a vein, called a sinus. 



From a point against 4 the lining also extends forward, arching upward, 

 and forms a shelf called TENTORIUM, to the upper surface of which the 

 back part of the Falx is attached. The Tentorium supports the back part 

 of each large Brain, and covers and protects from pressure the small 

 Brains. The Falx supports the upper brain when the head rests upon 

 either side. The Cranium is thus divided into three cavities, neither com- 

 pletely closed, the two upper ones corresponding to and containing the 

 right and left cerebri, and the lower one the cerebellum. 



Describe Fi?. 160. What relation has the back of the nose to the spinal col- 

 umu? What tho mouth ? 



