Hugo Münsterberg

THE PHYSIOLOGICAL BASIS OF MENTAL LIFE

most interesting of valleys, Clarks Fork of the Yellowstone, still impressed with the many unsolved problems connected with the geology of the range. I at first visited the region in -the expectation of finding a partially submerged range of Paleozoic and Mesozoic sediments. If ever snch range existed, it had completely disappeared by profound subsidence. I then looked for the roots of some powerful dominating volcano which had been the source of the varying breccias, but this also I failed to discover. In its stead, if I interpret the facts correctly, I found penetrating the breccias the towering domes and pinnacles of granular and porphyritic rocks, which in some fardistant day, when denudation has removed a greater part of the overlying mass, may be found to form one connected body which erosion has already so far laid bare as to indicate that they all form a part of one broad complex of coarsely crystalline rock of early Tertiary age. ARNOLD HAGUE. U. S. GEOLOGICAL SURVEY, WASHINGTON, D. C.