86 'Journal of Comparative Neurology and Psychology. 



PLATE I. 



Fig. I. Photograph of a section of ganglion of Limaz, fixed in absolute alcohol and stained by iron- 

 haematoxyln. The cells show many vacuoles of various sizes in the cytoplasm, some of which contain 

 solid bodies. 



Fig. 2. Same as above, under higher magnification, j\>inch oil immersion lens used in making photo- 

 graph. 



Fig. 3. Photograph of a living nerve cell of Planorbis under j.; inch oil immersion lens. Note 

 the very large nucleus and mass of pigment granules at the axone hillock of cell. 



Figs. 4 and 5. Photographs of sections of ganglion of Planorbis, fixed in osmic acid, unstained. 

 The dark bodies are the same as those shown in Fig. 3. 



