532 SPORADIC DISEASES. 



frequent symptom — there will be a tendency to keep the head 

 in a depressed position. In one case this depression of the head 

 was very marked, but this did not happen until the animal — a 

 mare — was worked or exercised ; when kept quiet it appeared 

 in the best of health in every way, but if exercised, no matter 

 how slowly, depression of the head — the nose being almost 

 brought to the ground — would always occur. This animal had, 

 shortly before presenting these signs, recovered from an attack 

 of farcy, affecting the cervical and facial absorbents. When I 

 saw it I expressed an opinion that there was a tumour in or 

 upon the brain, due to or connected with the previous farcy. 

 I may mention that the cervical lymphatics were still enlarged, 

 but showed no signs of recent inflammation. The probable age 

 of these ventriciilar tumours is sometimes a question of im- 

 portance as connected with the soundness of a horse prior to 

 purchase ; and it is well to bear this in mind, as an animal may 

 die from an attack of cephalic disease, and upon a post mortem 

 examination being made, these tumours may be found in the 

 lateral ventricles. The clinical history of these points out that 

 they are of slow growth ; that they do not cause any disturbance 

 until they have attained a certain size ; they do not, at least in 

 all the instances that I have met with or heard of, give rise 

 to disturbance, increasing in severity as they slowly grow ; but 

 all at once, when they have attained the size of a small egg, 

 signs of a severe cerebral disease occur, which ultimately proves 

 fatal. Examination of the brain and tumours reveals — 1st. The 

 lateral ventricles nearly or completely filled by the growths; 

 2d. The tumours themselves firmly encapsuled in the folds of 

 the choroid plexus ; od. Absence of congestion, injection of the 

 vessels, and other signs of recent inflammation ; and 4:th. A 

 caseous and calcareous change of the interior of the tumours. 



Tliickcning of the dura inciter. — Thickening and induration of 

 the dura mater consequent upon a slow chronic inflammation 

 is of very rare occurrence. I have one case on record, however, 

 in which the dura mater attained a thickness varying from one 

 inch at the base to several inches at the anterior part of the 

 cranium, causing absorption of the descending (orbital) plates of 

 the frontal bones and wings of the ethmoid, and filling the 

 frontal sinuses. The horse in which this was discovered had. 

 presented signs of brain disease, coma, immobility, partial 



