428 DISEASES OF THE NERVOUS SYSTEM. 



The lesion exists most frequently in the cerebellum and is 

 more common in the young than later in life. 



Syphilis: Gummata of the brain nearly always originate 

 primarily in the meninges. A syphilitic endarteritis may also 

 produce diffuse or circumscribed changes in the brain-tissue. 



Tumors of the brain are of especial importance by reason of 

 the inflammatory and degenerative changes resulting from 



FIG. 197. 



Sarcoma developed between the hemispheres, posteriorly (U. S. A~TMuseum, No. 8400). 



their pressure on the brain- tissue. The glioma is the tumor 

 most frequently met; it is generally solitary and grows always 

 from the neuroglia-tissue never from the pia. fiarcoma oc- 

 curs next in frequency generally the round-celled variety. 

 (Figs. 196 and 197.) Carcinoma may occur as a metastatic 

 growth in the brain, but never primarily. 



