EXPLANATION OF THE PLATES. 193 



PLATE XII. 



ELEMENTS OP NERVE TISSUE. 



FIG. I. Nerve fibres. 1, Nerve fibres of the large variety ; 

 2, envelope of the fibres ; 3, its contents ; 4, another fibre 

 treated by chromic acid ; 5, envelope ; 6, medulla ; 7, axis 

 cylinder ; 8, fine nerve fibres with a single outline, taken from 

 the spinal marrow. 



FIG. H. Fibres of Remak taken from a sympathetic gan : 

 glion from the lumbar region. 



FIG. III. and IV. Connexion between nerve-fibres and 

 ganglionic cells (after Leydig). 



FIG. Y. Connexion between nerve-fibres and cells of 

 the spinal marrow. 1, Central canal of the medulla spinalis ; 

 2, nerve-cells ; 3, superior prolongation ; 4, inferior prolonga- 

 tion ; 5, anterior root ; 6, posterior root ; 7, transverse pro- 

 longation forming the anterior commissure and establishing anas- 

 tomoses between the cells of the two halves of the spinal mar- 

 row (after Owsjauikow). 



FIG. VI. Nerve-cells. 1, Cells with one prolongation 

 (unipolar) from a dorsal ganglion of the sympathetic ; 2, ano- 

 ther cell from the ganglion of Gasser (on the fifth cranial 

 nerve) ; 3, mass of pigment. 



PLATE XIII. 



ELEMENTS OF NERVE TISSUE. 



FIG. I. Nerve cells. 1, Simple (apolar) cells from the grey 

 matter of the brain ; 2, multipolar cells from the grey matter 

 of the cerebellum ; 3, cell from the floor of the fourth ventricle ; 

 4, another cell from the grey matter of the cord in the cervical 

 region; 5, nucleus; 6, mass of pigment surrounding the 

 nucleus ; 7, two cells from the ganglion of Gasser ; one of them 

 has a nucleated envelope (8). 



