9. =Ventricles.= Contain about a teaspoonful of clear fluid. This may become purulent, cloudy, hemorrhagic, fibrinous. Note size of ventricles and horns. (Fluid increased and ventricles dilated in hydrocephalus.) Character of ependyma normally gray-red, delicate; may be pale or red, indurated, thickened, roughened (chronic ependymitis), hemorrhagic, etc. Compare floors of lateral ventricles as to symmetry (corpus striatum large in hemorrhages), color, etc. Adhesions are found most frequently in posterior horns. A fine granulation of the ependyma is caused by miliary tubercles. Large solitary tubercles may be found in the ventricles. Do not mistake postmortem softening of ependyma for pathologic changes. In the third ventricle note the presence of any abnormal contents, character of wall, symmetry of corpora quadrigemina, etc. Look for same changes in fourth ventricle as in lateral. Lining is gray-white and delicate; floor should be gray-white, firm, and show anatomic structures. Gray sclerotic areas are often present in floor. Solitary tubercles, tumors (glioma, neuroepithelioma, gliosarcoma, sarcoma), dermoids and cysticercus-cysts may be found here. Examine aqueduct of Sylvius for abnormal contents. 10. =Chorioid Plexus.= The tela chorioidea is normally delicate and translucent. Note color (red, pale, cloudy), swelling, purulent infiltration, condition of blood-vessels, tubercles, etc. Psammoma, sarcoma, papillary epithelioma, carcinoma, fibroma, angioma, cholesteatoma, cysticercus and echinococcus may be found in the tela and plexus. Cysts due to œdema are very common, also aneurismal dilatations of the vessels. In cases of hydrocephalus the veins of Galen should be examined for thrombi or compression from without. In acute hydrocephalus the plexus is deep red; hyperæmic, its vessels distended with blood. 11. =Pineal Gland.= The most common pathologic findings are: psammoma, adenoma, teratoma, sarcoma, formation of cysts (hydrops cysticus glandulæ pinealis), hypertrophy, abscess (purulent meningitis), metastatic tumors. In all cases of giantism especial attention should be paid to the pineal gland as well as to the hypophysis. 12. =Cerebral Ganglia.= Color, consistence, moisture, blood-content, hemorrhage, degeneration, sclerosis. 13. =Peduncles.= As above. 14. =Cerebellum.= Cerebellar cortex is 2 mm. thick, grayish-red in color. Note irregularities in thickness, color, consistence, blood-content, moisture. Compare hemispheres. White substance should be shining and moist. Abscesses, tubercles (solitary or conglomerate), gummata and neoplasms are the most common pathologic conditions. 15. =Pons.= Consistence firm normally. Note blood-content, relation of white and gray stripes, hemorrhage, degenerations, cysts, neoplasms, etc. 16. =Medulla.= Color grayish-white, consistence firm. Note blood-content, hemorrhages, degenerations and cysts (syringomyelia).