In a long-term study of the blood vessels of the brain,1-3contrast media were used as injection masses to demonstrate on roentgen film the course and cerebral relationship of these vessels. One of these media was a water solution of lead (lead sulfamate*), which, when injected into either the internal cerebral veins or the arteries coursing over the cerebral cortex, filled a myriad of fine venous channels traversing the white matter of the cerebral hemisphere. Interconnections between the superficial and the deep venous system of the cerebral hemispheres, through blood vessels traversing the white matter, have been postulated by others. Ekker,4in 1853, and Duret,5in 1874, presumed the presence of venous channels connecting the superficial and deep veins of the brain. Pfeifer,6in 1930, using microscopic methods, showed clearly anastomotic blood channels in the white matter of the brain. Schlesinger,7in 1939, producing venous