meninges and floating the membrane in mercuric chloride or formalin fixing-fluids. After a few minutes’ fixation the tubercles appear as minute grayish or opaque points, the membrane often appearing as if sprinkled with fine sand or powder. The Pacchionian bodies of the arachnoid must not be mistaken for tubercles. They are grayish in color, and most abundant along the longitudinal sinus. The meninges over the two hemispheres should be compared as to transparency, thickness, blood-content, amount of fluid in arachnoideal space, etc. The most important pathologic conditions of the inner meninges are anæmia, hyperæmia, stasis (asphyxia), œdema, hemorrhages (stasis, anthrax, aneurism, atheroma, infective emboli), serous, purulent and fibrinous inflammation (pyogenic cocci, bacillus pneumoniæ, pneumococcus, bac. coli, diplococcus intracellularis), chronic leptomeningitis (syphilis, alcoholism, toxæmia, etc.), tuberculosis, syphilis (gummatous meningitis), blastomycosis, actinomycosis and neoplasms. The last named are not common. Cholesteatoma, hæmangioma, lymphangioma, endothelioma, fibroma, osteoma and lipoma represent the benign tumors found here. Primary sarcoma is the most common tumor, usually angiosarcoma, perithelioma, cylindroma, round-cell-, spindle-cell- or myxosarcoma. Secondary sarcoma and carcinoma occur. Animal parasites are cysticercus and echinococcus. 8. =Cerebrum.= Weight of brain as a whole 1,200-1,400 grms. (15-50th year). Cerebrum averages 1,039 grms. in the female, 1,155 grms. in the male. A weight of 1,100 grms. may be taken as the minimum normal, and 1,700 grms. as the maximum for the brain as a whole. The relation of the brain-weight to that of the body is 2-100. In old age there is a loss of weight. Sagittal diameter 15-17 cm., transverse 14, vertical 12.5 cm.