CHAP, vi.] THE BRAIN. 647 



through the foramen of Majendie, from the cranium into the spinal 

 canal, the walls of which are less rigidly complete, prevents any 

 injurious intracranial compression. Experimental evidence how- 

 ever, as far as it goes, does not lend any very great support to this 

 view ; and though removal of the fluid by aspiration is said to lead 

 to haemorrhage from the pia mater and to various nervous disorders, 

 the value of the cerebro-spinal fluid depends in all probability more 

 on its physiological properties as lymph, than on its mechanical 

 properties as a mere fluid. 



