PLATE 2 



EXPLANATION OF FIGURES 



4 Anterior cell, frozen and fixed at about — 25°C., one minute and forty-three 

 seconds after decapitation. This is a more advanced stage than figure 3, but 

 there are still evident traces of the Nissl's bodies from which the network was 

 derived. The nucleus is faintly discernible. Magnification 400 diameters. 



5 Anterior horn cell, frozen and fixed at about — 25°C., one minute and forty- 

 three seconds after decapitation. From the same smear as figure 4. This repre- 

 sents one of the extreme forms in which practically all evidence of the former 

 Nissl's bodies is lost. In the area marked A' there is observed a small portion 

 of the extracellular pink-staining network which is continuous with the intra- 

 cellular blue-staining reticulum. This area in this figure is the only place where 

 any of the pink-staining network is shown. The nucleus is represented by the 

 area having but few meshes. The nvicleolus is much distorted. Magnification 

 600 diameters. 



6 A somewhat diagrammatic representation of MoUgaard's 'perivascular net- 

 work' in the walls of a precapillary vessel. Frozen and fixed at about — 40°C., 

 forty-two seconds after decapitation. From a smear of neural tissue. Note that 

 some of the networks extend beyond the nuclear walls while others are still 

 confined within them. In those extending beyond the limits of the nucleus the 

 nuclear wall is apparently lost in the network. Magnification 1000 diameters 



348 



