318 THOMAS J. HELDT 



Although he finds no Nissl's bodies, Mollgaard's observes in 

 the Vitally-fixed' and stained nerve cell a network, which he 

 interprets as a 'glia-network,' and whose richness depends on the 

 time after death the preparation is made. In the cells of a 

 piece of tissue taken from the living animal and Vitally-fixed' 

 and stained he 'finds a network consisting at most of three to 

 four coarse meshes, while in cells of preparations made ten to 

 twelve minutes after death the network reaches its greatest devel- 

 opment. In 'vitally-fixed' tissue the cell protoplasm lying be- 

 tween the meshes of this network remains wholly unstained with 

 toluidin-blue for some time after the tissue is taken, and onl}'' 

 becomes stainable one and one-half to four hours after death, 

 during which time the reaction of the brain substance has become 

 increasingly acid. As the time after death increases the cellular 

 protoplasm within the meshes of the networks of the cells becomes 

 more and more stainable. But at about fifteen to twenty hours 

 post-mortem the network itself, on the other hand, begins to 

 disintegrate and forms peculiar aggregated masses. The signifi- 

 cance of these masses will be mentioned later. 



The technique may be varied as follows : A small piece of nerve 

 tissue is taken seven minutes after death, is frozen, and placed 

 in 96 per cent alcohol at room temperature and left for one and 

 one-half to two hours. Then it is cut and fixed in alcohol at 

 — 20°C., and finally stained with toluidin-blue. With this treat- 

 ment Mollgaard says that the network begins to shrink and 

 disintegrate. If the tissue is left in the alcohol at room tem- 

 perature for about twelve hours before being cut and stained he 

 finds an additional structure present, namely, granulations. These 

 granulations, in his own words: ''gleichen .... voU- 

 standig den Nissl-Kornern." The networks of the cells in which 

 the granulations are present, he finds, on close examination, to 

 be composed of a series of closely placed granules. Hence Moll- 

 gaard believes that in tissue taken at various intervals after 

 death the networks of the Vitally-fixed' nerve cells gradually 

 degenerate into the peculiar masses and granulations mentioned 

 above, which are apparently Nissl's bodies. To quote again, he 

 says: ''Wir haben gezeigt oder jedenfalls in hochsten Grade 



