304 PHYSIOLOGY CHAI>. 



more liable to be affected than others. The spinal cord of the 

 aged often shows marked fibrous sclerosis of the blood-vessels. 



Most writers consider the integrity of the cerebellum in old 

 age as being in obvious contrast to the atrophy found in other 

 parts of the encephalon ; this integrity of the cerebellum is not 

 however absolute, as was shown by Anglade and Calmetta 

 in 1907. The senile changes in the cerebellum are not ,marked 



FIG. 123. Cerebral cortex of an old man aged 102 years, treated according to Bielschow.sky's 

 method ; low magnification. The whole of the grey matter is sprinkled with miliary necroses 

 (senile patches) of Redlich-Fischer. (Micro-photograph by Dr. Perusini.) 



by atrophy in toto, but by partial atrophy of a very circumscribed 

 order resulting in the establishment of the perivascular foci known 

 as the lacunae of disintegration, which occur most frequently in 

 the limiting sulci of the cerebellar lamellae. 



The changes which take place in the brain of the aged are of 

 the greatest importance to the subject of natural senility. 

 Pathological anatomy has recently succeeded in finding one 

 change in the brain which is peculiar to senile involution, 

 whereas hitherto nothing really specific in this direction has been 



