410 £rof. C. Frommann, 



demonstrated that thin slices of the gray substance of an animal 

 recently killed, the tissues of which are still living, exhibit with 

 high powers of the microscope, without further treatment, very 

 conspicuous changes in the configuration of the reticulum , which 

 moves, contracts and expands for quite a time, if kept in a liquid 

 favorable to the life of the specimen , such as warmed serum of 

 blood. Thus it was directly proved, that the gray matter consists 

 of living matter in a reticular arrangement." 



