The association of lesionr» at the base oflhe tlieneephalon w| lh abnormal oheail} in both man and animals has heen observed many timea. As a ntsull of these ohservatiom il is quite generally helieved that wme structure. etther neural or glandular. situated in this region is involved in the metabolism of this. There is however. the most emphatic disagreement concerning the nature of the re_\_: uIu: ury mechanism. ii ill ii

The considerable confusion still persistmg regarding the relative impommec of the hypnthalamic and the hy pophysiul factors in patlmlogicul obesity ol'lhi:. t) 11-L ‘ham made a re-examination of the whole question seem desirable. There appear:-. moreover, to be no clear-cut notion. even on the part of thoase who have supported its primary rule. us to exactly what structures in the hypothalamus mu.-at be dc-slroyetl to obtain this derangement of fat metabolism. In an effort to bring these problems u step nearer solution the following experiments wen: begun.