DISEASES OF THE BRAIN AND NERVOUS SYSTEM. ol 



;tn<l in the fissures. According to Rilliet and Barthez, they are 

 more frequent upon the convex surface of the hemispheres than at 

 the base. Dr. Hamernjh found them more frequently at or near 

 the base of the brain. They are much more abundant upon the 

 brain than upon the cerebellum. They are met with, also, imbed- 

 ded in the gray matter of the brain, and are here often surrounded 

 by a halo of redness, usually connected with an enlarged vessel, 

 ra mifying from the pia mater. More rarely, tubercles are detected in 

 /he medullary portion of the brain, where they are often overlooked, 

 in consequence of their pale, semi-transparent, yellowish tint. The 

 plexus choroides is, also, often covered with tubercles. They are 

 very commonly met with, likewise, on the serous membranes of 

 the thorax and abdomen, in the lungs, and occasionally in the sub- 

 stance of the liver. In twenty-seven out of thirty-three cases of 

 hydrocephalus, Barthez and Rilliet found tubercles or granula- 

 tions associated with inflammation of the pia mater ; in four cases 

 the meningitis was unattended by any trace of tubercular deposition 

 in the encephalon; and in two cases the granulations, or meningial 

 tubercles, were unattended with any traces of inflammation. In all 

 the thirty-three cases the symptoms were nearly identical." 



Causes. — Among the causes of this disease, therefore, we may 

 consider the scrofulous diathesis as being the most potent ; yet we 

 can not always prove the fact until after the death of our patient. 

 Yet an autopsy held on such a case is really valuable to the inquiring 

 mind ; for, in discovering the true pathology of the affection, we are 

 not only enabled to comprehend its character, but also the modus 

 operandi of treatment. 



The exciting causes of the malady are not always so apparent. 

 The authoi has known it to follow castration, puncture of the foot, 

 staggers, and acute disease of the stomach. 



In some cases, faulty nutrition is the exciting cause; in shcrt, 

 the symptoms sometimes supervene on the subsidence of some 

 other malady. 



Symptoms. — As regards the symptoms of hydrocephalus, they do 

 not differ materially from those alluded to in the preceding article. 

 At first, torpor, unconsciousness, unsteadiness on moving ; dilation 

 of the pupil ; the animal gets upon the floor, in many cases never 

 to rise again. Stertorous (grunting) breathing takes place ; the ani- 

 mal tosses his head about in an unnatural manner, often throwing 

 it backwaid — a very noticeable feature of this affection — occasioo- 



