INFLAMMATION OF THE BBAIN. 207 



femic, loosened, and covered by fibrinous exudation. The cover- 

 ings of the brain are almost always infiltrated and detached from 

 the pia mater with difficulty and according to the amount of 

 inflammation and purulent fluid that may be found in the ven- 

 tricle. In a chronic case we have a circumscribed thickenino- of 

 the cerebral membranes and adhesions uniting the coverings with 

 the brain, etc. 



3. Inflammation of the Brain Mass. Encephalitis. This dis- 

 ease, as a rule, involves single centres and causes a general irrita- 

 tion of the healthy tissue without any distinctly marked limit. 

 In the affected regions the substance of the brain is swollen, 

 hyperaemic, and frequently filled with small hemorrhagic centres. 

 In the course of time the inflamed cerebral substance becomes 

 softened and pulpy. This condition may be present without any 

 hemorrhage, but as a rule the brain matter becomes red and finally 

 yellowish. This latter color is due to metamorphosis of the color- 

 ing substance of the blood or to fatty degeneration. These con- 

 ditions are divided into white, redj or yellow — softening of the 

 brain. Finally cicatrices and cysts are formed, as in apoplexy, 

 or an abscess may be developed which is filled with thick yellow 

 or greenish pus, and becomes encysted and sometimes solidified 

 (calcareous). In some cases small encephalitic centres may heal 

 without leaving any trace. In some cases we see the development 

 of a (non-inflammatory) softening of the brain with thrombosis 

 and embolus of the arteries; and, as a general rule, we find 

 symptoms which resemble apoplexy very much. 



Clinical Symptoms. The symptoms of inflammation of the 

 brain in its early stages resemble those of hyperaemia. The ani- 

 mals are excited; they run aimlessly from one side to the other, 

 and are fretful and irritable. They whine and howl constantly. 

 The head is hot; the conjunctiva is more or less reddened, the 

 pupils are contracted, and the reflex action is very slight. The 

 appetite is lost; constipation is generally present, and more or less 

 vomiting. The patient is indifferent to the impressions of exter- 

 nal objects, being sleepy and apathetic. Soon the disease changes 

 in its character. "We see acute convulsions, especially those of the 

 jaw, or eclamptic convulsions. The animals cry and howl. At 

 the same time the sphincters are relapsed, the animal apparently 

 having no control of them. Then there is an interval of quiet- 



