358 



PLATE VIII 



Fig. 1, a-b. Isolated axis-cylinder from the ischiadic nerve of Rana esculenta. 

 Fixed with pier o- sulphuric acid, followed by alcohol, and finally stained 

 in the usual way with aurichloride of potassium. 1, a, with remains of 

 the medullary sheath sticking to it. 1, b, probably from the region of 

 a constriction. Optical longitudinal section. 1, a, x about 3300, 1, 

 &, x about 2700. 



Fig. 2. Nucleus, with surrounding protoplasm, of a ganglion cell from the 

 spinal cord of Bos taurus (juv). Macerated in iodine-alcohol (10-15 per 

 cent). Shows distinctly the vertical position assumed by the alveoli 

 directly surrounding the nucleus with regard to its surface. 



Fig. 3. Small portion of the margin of an isolated ganglion cell from the 

 ventral nerve cord of Lumbricus terrestris, showing the alveolar layer 

 distinctly. Maceration in iodine-alcohol (10 per cent). 



Fig. 4, a-c. Isolated connective tissue cells from the ischiadic nerve of Rana 

 esculenta, 4, a, several connected cells under low magnification. 4, &, 

 single cells under stronger magnification in lateral view. 4, c, the same 

 in surface view. Picro-sulphuric-osmic acid, n, nucleus. 



