THE BRAIN 187 



The guinea-pig was killed June 16th. The autopsy was 

 negative except for a slightly enlarged spleen. Histological 

 examination of the brain showed numerous lesions of typhus 

 in the cerebrum and cerebellum. 



One of the three guinea-pigs inoculated with an emulsion of 

 the brain of guinea-pig 387 reacted in a manner typical of 

 typhus, and the others showed less marked febrile reactions 

 at the same period. 



Record of guinea-pig III D inoculated with brain emulsion 

 of guinea-pig 387 : 



F. F. 



June 16 102.7 June 28 103.2 



17 103.0 29 103.8 



18 102.7 30 103.2 



19 No record July 1 103.7 



20 102.3 " 2 102.8 



21 . . 102.8 3 . . No record 



22 102.6 



23 103.3 



24 103.6 



25 104.3 



26 No record 



27 . . 103.0 



4 No record 



5 104.5 



6 105.0 



7 No record 



8 105.2 



9 . . 105.6 



The guinea-pig was killed on July 9th for diagnosis. The 

 autopsy showed an enlarged spleen covered with a thin fibrin- 

 like layer. The peritoneum as a whole was normal in appear- 

 ance. The other organs were normal. Histological examination 

 of the brain showed many typical typhus lesions. 



(t) The pituitary body: The pituitary body from twenty- 

 one cases was studied histologically. No lesions of blood ves- 

 sels or parenchyma were found in the anterior or glandular 

 lobe. Vascular and proliferative lesions of the posterior lobe 

 were found in eleven cases. Nowhere else in the body is there 

 an equally striking illustration of the selective localization of 

 the typhus virus, and an explanation why blood vessels in the 

 posterior lobe are affected while those of the anterior lobe 

 escape involves the general consideration of the pathology of 

 nerve tissues. 



The proliferative lesions in the pituitary resemble those in 

 the brain; but the participation of the neuroglia is beyond 



