showing that a number of small veins from the cranial bones 

 have been ruptured. The degree of adhesion between the 

 dura mater and the inner surface of the cranial bones varies 

 in different subjects and in different localities. In all cases 

 it is strongly adherent along the lines of the sutures, like 

 the pericranium externally; and, further, it is much more firmly 

 attached to the base than to the vault of the cranium. In the 

 child indeed, as long as the bones of the cranium are grow- 

 ing it is more adherent than in the adult ; and it is more 

 firmly bound to the bone again in old age. 



The dissectors should now clean the- outer surface of the 

 dura mater with a sponge. They will then recognise the middle 



Arachnoideal granulation Opening of cerebral vein 



f^- 



FIG. 30. Median section through the Frontal Bone and corresponding part of 

 the Superior Sagittal Blood Sinus. The arachnoideal granulations are 

 seen protruding into the sinus. (Enlarged. ) 



meningeal artery upon each side, ascending in the substance 

 of the outer part of the membrane, and sending off its 

 branches in a widely arborescent manner. It stands out in 

 bold relief from the membrane. If the skull-cap is examined, 

 its inner surface will be observed to be deeply grooved by 

 the artery and its branches, and by the veins which accom- 

 pany and lie external to them (Wood Jones). The meningeal 

 arteries are not intended for the supply of the membrane 

 alone, as the name might lead one to imagine. They are 

 also- the .nutrient .vessels of -th^Jrtner table and diploe of the 

 c rarvia 1 bone-s (Fig, ^ 3 2 )." ^ 



Grranulatipnes Arachnoideales (O.T. Pacchionian Bodies). 

 Tbe afaohhoideal . granulations are almost invariably present, 

 and; as a -rule, arc- best markred in old subjects. They are 

 small granular bodies, ranged in clusters on each side of 



