Black pigment tumors have been found in connection with the brain and especially the meninges, varying in size from a pea to a walnut, and as a rule, secondary to similar formations elsewhere. They are most common in gray horses which have turned white, and may give rise to gradually advancing nervous disorder. Bouley and Goubaux record a case of this kind attended with general paralysis. W. Williams reports the case of an aged gray stallion with melanomata on the meninges and in the brain substance which were associated with stringhalt of old standing. Mollereau in a vertiginous horse found a pigmented sarcoma in the right hemisphere between the gray and white matter, and like an olive in size and shape. There were melanomata around the anus. (Annales de Medecine Veterinaire, 1889). So far as such have been examined they follow the usual rule in melanomata in having a sarcomatous structure. While it is impossible to make a certain diagnosis without opening the cranium, the condition may be suspected, in gray horses, when melanotic tumors are abundant in the usual external situations (anus, vulva, tail, mammæ, sheath, lips, eyelids, etc.), and when brain symptoms set in and progress slowly in such a way as to suggest the gradual growth of a tumor. _Treatment_ is hopeless, since if they have invaded the brain, the tumors are likely to be multiple in the organ, and numerous and widely scattered elsewhere. PSAMMOMATA (GRITTY TUMORS) OF THE BRAIN. As already noted these sandy tumors are often the advanced stage of cholesteatomata, the abundance of the phosphate of lime leading to its precipitation in the neoplasm. The same cretaceous deposit often takes place in old standing tumors of other kinds, as in melanoma, and fibroma so that the sandy neoplasm may be looked upon as a calcareous degeneration of various forms of intracranial tumors. The same tendency to calcareous deposit is seen in the tuber cinereum (pineal body) of the healthy brain which has taken its name from the contained gritty matter. This tendency to the precipitation of earthy salts may be further recognized in the osteid tumors which occasionally grow from the dura mater. The gritty tumors are especially found in the older horses in which the tendency is greatest to extension of ossification and calcic degenerations. Like other tumors these may attain a considerable size before they give rise to any very appreciable symptoms, but having attained a given development—often the size of a walnut, they become the occasion of nervous irritation, delirium and disorder, as indicated under encephalic hyperæmia and inflammation, cholesteatomata, etc. There may, however, be drowsiness, stupor, coma, or paralysis as the exclusive symptom, or there may be spasms and convulsions. MYXOMA OF THE BRAIN.