218 DISEASES OF THE BRAIN. 



of a ventricle, it often breaks through the wall of the latter, and its 

 blood escapes into the ventricle. Haemorrhagic effusions, lying near 

 the surface of the brain, not unfrequently break through the cortical 

 substance and pia mater, so that the blood enters the subarachnoid 

 space. Usually there is only one haemorrhagic effusion in the brain, 

 rarely several. Their most frequent locality is the corpus striatum, 

 the thalamus opticus, and the large medullary masses of the hemi- 

 spheres ; less frequently they occur in the cortical substance of the 

 cerebrum, in the cerebellum and pons. Apoplexies in the corpora 

 quadrigemina and medulla oblongata are rare, and they hardly ever 

 occur in the corpus callosum and fornix. The contents of a recent 

 apoplectic clot consist of blood and broken-down brain-substance. The 

 blood either remains fluid or is partly coagulated, and then the fibrin 

 is occasionally deposited at the periphery, while the middle of the clot 

 consists of fluid blood. Changes of the contents and walls of the clot 

 soon begin. The fibrin of the blood and the portions of brain mingled 

 with the effusion break down into a detritus, the contents become 

 more fluid, the dark-red color becomes brown, then saffron yellow. 

 Granular pigment and often also haematoidin crystals are formed from 

 the hasmatin. At the same time, in the immediate vicinity of the clot, 

 there is a new formation of connective tissue starting from the neu- 

 roglia, which develops into a thick, hard layer that encloses the clot. 

 In the same way there is a new formation of delicate connective tissue, 

 colored yellow by the pigment contents and serous infiltration, which 

 covers the wails and traverses the clot as a fine network. After the 

 elements of the effusion have broken down, all its remains disappear, 

 while their place is gradually supplied by serum ; and then we find in 

 the brain a cavity filled with clear liquid, surrounded by a callous sub- 

 stance, and covered and traversed by delicate yellow-colored connec- 

 tive tissue an apoplectic cyst. The cysts usually remain permanently. 

 But occasionally the serum is reabsorbed, the walls approximate, and 

 finally are only separated by a stratum of pigment. These callous 

 spots, enclosing pigment striae, are called apoplectic cicatrices. The 

 cicatrization of a haemorrhagic effusion in the cortical substance is 

 somewhat different. The effusion of blood under the pia mater, which 

 is usually flat and extended, undergoes the same changes as do the 

 contents of central clots. The red pulp gradually becomes a reddish- 

 brown or saffron-yellow crumbly mass, which is bounded below by 

 callous brain-substance, above by the pia mater. Lastly, we find an 

 excavated pigmented plate, above which a serous effusion fills the cav- 

 ity resulting from the depression. While the above terminations of 

 cerebral haemorrhages must be regarded as the most favorable, in 

 some cases the reactive inflammation in the vicinity of the broken 



