488 CEREBRAL APOPLEXY. 



appearances and microscopical characters. Lying on the 

 posterior lobe of the left hemisphere, I found a solid and 

 nearly spherical tumour, 2*2 inches long and 1-6 inches 

 broad. On raising it, it proved completely detached from 

 the cerebral mass, and divided into two portions, a lesser 

 internal and posterior, and a larger external, the two applied 

 by a flattened surface as if severed by a section. 



The upper part of the tumour is covered by a dense 

 white membrane, only partially adherent, and which ap- 

 pears to be a somewhat thickened portion of dura mater. 

 Directly beneath and around the tumour are a number of 

 flattened stratified scales. The separate layers are shiny 

 and brittle, and prove by the microscope to be solidified 

 lymph, without the slightest morphological character. The 

 whole of the thickened portion of dura mater above-men- 

 tioned is lined by a dense coating of super-imposed strata of 

 the same solidified fibrin. 



A section through the middle of the tumour discloses 

 that it is a solid mass of coagulated blood, undergoing the 

 usual changes of apoplectic effusions. It is of a deep red 

 colour, indicating its comparatively recent origin, though, 

 from the colourless external strata, I should be led to sup- 

 pose that the animal had suffered from apoplectic effusion 

 at two distinct and distant periods. 



The posterior lobe of the brain is evidently, to some 

 extent, atrophied, though the amount of flattening is decep- 

 tive, as in all recent apoplexies, and sufficiently explains 

 the irrecoverable cerebral disturbance. 



On the whole, the brain appears to have been the seat 

 of some determination of blood, but had a remarkably 

 healthy appearance, with the exception of the two choroid 

 plexuses, which are slightly thickened from a deposit of 

 eholesterine, as commonly found in aged horses." 



