The purpose of this paper is to report 12 cases of spongioblastoma polare,1 to correlate them with those of other authors and to analyze them from the clinical and pathologic point of view. Cases of glioma of this type have been reported singly and in small groups under several names. Some of these series of cases have dealt with spongioblastoma of a limited region, such as the optic nerve or brain stem. Cushing's group of 32 cases is the only large series which dealt with spongioblastoma of the brain as a whole. The 12 tumors reported on in this paper constitute all the spongioblastomas which occurred in a series of 263 microscopically confirmed cerebral gliomas, obtained at operation or necropsy at the University Hospital between July 1, 1930, and July 1, 1935. In 8 cases the tumor was in the posterior fossa of the skull; in 3, in the optic