36o 



PLATE IX 



Fig. 1. Small portion of an isolated capillary from the spinal cord of So 

 taurus (juv) in optical longitudinal section, n, two nuclei of the wall. 

 At o the surface structure of the protoplasm of the cells of the wall is 

 depicted for a short distance. Maceration in iodine-alcohol (10-15 per 

 cent). 



Fig. 2. Broad protoplasmic process of a ganglion cell from the spinal cord 

 of Bos taurus (juv}. Fibrillated alveolar structure very distinct. Macera- 

 tion in iodine-alcohol (10-15 per cent), x about 2000. 



Fig. 3. Isolated axis-cylinder of the gray substance of the spinal cord of Bos 

 taurus (juv}. Optical longitudinal section. Maceration in iodine-alcohol 

 (10-15 per cent), x about 4400. 



Fig. 4, a-c. Transverse sections of medullated nerve fibres from the 

 ischiadic of Rana esculenta. Picro-sulphuric acid. Fat removed with 

 alcohol and ether. Stained partly with hsematoxylin, partly with gold 

 chloride. 4, a, transverse section between two constrictions. 4, b, 

 transverse section in the region of a constriction. 4, c, transverse 

 section through a nucleus (n) of the sheath of Schwann. s, sheath of 

 Schwann. a, so-called sheath of axis-cylinder which was in part very 

 distinct. In 4, c, the sheath of Schwann is probably rather abnormally 

 distorted. 



