That the cerebrospinal fluid passes both into the venous sinuses and into the cervical lymph nodes has been adequately demonstrated by Key and Retzius and more recently by Weed and his co-workers. A review of the literature is unnecessary, as the latter group has covered it in detail. We simply wish to point out that there are now available two agents with which one can demonstrate readily in the living that foreign material introduced into the subarachnoid space appears after a short period of time in the cervical lymph nodes both superficial and deep. The early work was with a brominized oil (brominol, light), the later with thorium dioxide (thorotrast) and it will be most convenient to describe the work in terms of these two agents. Dog no. 3 will illustrate what may occur with brominol; dog no. 12 with thorotrast.