Colloid degeneration, which has also been described under the title colloid milium or hyaloma, is a rare disease. I have been unable to find more than nineteen authentic cases reported in the literature since Wagner first described it in 1866. In addition to these genuine cases, a number of others have been reported by various writers which I feel cannot be accepted because they differ so materially, clinically as well as histologically, from the other cases cited. Liveing's1three cases reported under this title cannot be accepted as genuine, especially since he did not make any histologic examination of the lesions he described. Henry Fox2described a case of colloid degeneration of the skin, which later he himself admitted to be a case of acnitis, and therefore cannot be considered. One of Jarisch's cases published under the title of "Colloidoma Ulcerosum" should probably not be accepted either, although