The softening of the nervous tissue may result in a pulpy material, which in the comparative absence of blood is grayish (=gray softening=), if abundantly infiltrated with blood is red (=red softening=), if older and discolored is yellow, as in an old extravasation, (=yellow softening=), if thick and viscous is =gelatinoid softening=. If the exudate becomes organized into fibrous material it is a =connective tissue sclerosis= or a =cicatrix=. If the softening exudate becomes purulent it constitutes a =cerebral abscess=. Cerebral abscess is especially common as secondary abscess in strangles or contagious rhino-adenitis in the horse, but may occur as the result of the presence of any pyogenic germ. _Diagnosis._ While there is a certain similarity to =rabies=, the horse with encephalo-meningitis is distinguished by the absence of the extreme hyperæsthesia and irritability, of the persistent neighing and squealing, of the rapid alterations of the voice, hoarse and shrill, of the hallucinations, as following imaginary objects with the eyes, of the readiness to attack with teeth or heels when in any way disturbed or excited, of the disposition to get violently excited when a dog is brought near, or in the case of a stallion to show generative excitement. From =cerebral congestion= it is to be distinguished by the greater severity of the paroxysms, or the deeper character of the stupor, but above all by the presence of the hyperthermia and other indications of fever. =Immobility= which presents the symptoms of drowsiness, stupor and hebetude, is also unattended by fever, or anorexia, shows a healthy condition of the functions, of respiration, digestion and assimilation and a restful condition when left quiet and still. The _cerebral excitement_ that sometimes appears in =influenza= is really an encephalitis complication, but its specific cause is recognized in the local prevalence of the infectious disorder, and the inflammatory or catarrhal condition of the mucous membranes. The diagnostic manifestations of _meningitis_ and _encephalitis_ respectively are given under symptoms. _Symptoms in Cattle._ In cattle encephalo-meningitis supervenes on congestion, and sometimes comes on abruptly in connection with traumatic injuries, acute gastric disorder, leadpoisoning, or narcotism. The cases of cerebral parasitism are usually slow in their onset.