INFLAMMATION OF ERAIN SUBSTANCES. 267 



of an unduly prominent bone the effect will in the end be much 

 the same; not only will the meninges participate in the damage, 

 but the true brain substance also. The distinctive characteristics 

 of the cerebral and meningeal structures under the influence of 

 inflammation are set forth very clearly by the late Professor 

 Robertson in his work entitled '''Equine Medicine,''' in the fol- 

 lowing terms: " When the membranes are primarily affected there 

 is suddenness in development of symptoms, local congestion, ex- 

 citement with muscular spasms or convulsions, succeeded by sub- 

 sidence or arrest of normal nervous activity. Invasion of the true 

 cerebral structure, on the other hand, is less active in develop- 

 ment of symptoms, is marked by no frenzy or excitement, but 

 from the first exhibits lowered or depressed functional activity and 

 impairment at the outset of some special nerve function. In the 

 early stages of inflammation of the cerebral structures in all ani- 

 mals during which there is much muscular derangement, and par- 

 ticularly when the meninges seem more largely the seat of this 

 morbid action there is very likely to be excitement, delirium or 

 convulsions. The severity of these will be determined by the 

 extent of tissue invaded. This hyperactivity of cerebral function 

 is not constant or continuous, but paroxysmal in character, liable 

 to be brought on or seriously augmented by an}' untoward nois2 

 or disturbance to which the animal may be subject. The consti- 

 tutional fever is well marked, the temperature raised, skin and 

 mouth perceptibly hotter than natural; there seems pain in the 

 head, which the animal cannot bear to have roughly handled; the 

 eyes are staring and bloodshot, with pupils contracted; the pulse 

 frequent and hard or sharp; respiration irregular and .sometimes 

 accompanied with a moan; bowels confined. The animal is rest- 

 less and uneasy, moving from side to side or around his box, the 

 body sometimes damp with perspiration. Occasionally muscular 

 twitchings and general or local hypersethesia are symptoms well 

 marked. Succeeding this stage of increased nerv^ous irritability and 

 vascular excitement, which is generalh' short-lived, is that of 

 nervous aberration and depression, indicative of more extensive 

 involvement of the true nerve structures. The fever subsides, 

 the temperature of the body is lower, the pulse diminishes in fre- 

 quency, is less sharp or hard; the breathing becomes stertorous, 

 the delirium or excitability gradually declines, and special sensa- 



