— 213 — 
enveloping the spinal cord. grs Border of the grey sub- 
stance. np Nervous process. ppr Protoplasmic process. 
Fig 105. (Magnified 130 diameters). Ganglion cell, from a trans- 
verse section of the spinal cord of Myxine. np Nervous 
process or mixed process. ppr Protoplasmic process. 
vnr Nerve-tube of the ventral nerve-root. sh sheath enve- 
loping the spinal cord. 
» 106. (Magnified 130 diameters). Ganglion cell, from at trans- 
verse section of the spinal cord of Ilyxine. vnr Nerve- 
tube (of the ventral nerve-root) springing directly from 
the ganglion cell. sh Sheath envoloping the spinal cord. 
» 107. (Magnified 130 diameters). Mesial part of a transverse 
section through the spinal cord of Myxine. Plenty of 
nerve-tubes {nt) are seen in the section crossing the 
transverse commissures. cc Central canal. v Vacuoles. 
CGC Central epithelial cells with stained processes. sh Sheath 
enveloping the spinal cord. 
» 108. (Magnified 200 diameters). Neuroglia cells with their 
processes from a transverse section of the spinal cord. 
The black body in the centre is probably produced arti- 
ficially by the staining of several cells situated close 
together. sh Sheath enveloping the spinal cord. 
» 109. (Magnified 500 diameters). Part of a transverse section 
through the white substance of the spinal cord, showing 
how neuroglia fibres gather round the nerve-tubes of 
the ventral nerve-roots. p Ventral periphery of the spinal 
cord. grs Border of the grey substance. vnr Nerve-tube 
of the ventral nerve-root. hr Side-branch given oft" from 
this nerve-tube. f Neuroglia-fibres. nc Neuroglia-cells. 
gc Ganglion cell. ppr Protoplasmic process. (Pixed in 
saturated aqveous solution of picric acid, stained in accor- 
dance with Heidenhain's hæmatoxylin method). 
» 1 10. (Magnified 500 diameters). Neuroglia-fibres running trans- 
versally between the large nerve-tubes (Miillers nerve- 
tubes) in the white substance ; from a chromo-silver stained 
transverse section of the spinal cord of Myxine. mif Neu- 
roglia-fibres. Mnt Miillers nerve-tubes. pe Ventral peri- 
phery of the white substance. 
» III. (Magnified 80 diameters.) Part of a chromo-silver stained 
horisontal section of the spinal cord of Myxine; exhibiting 
the dichotomous subdivisions of the nerve-tubes of the 
