796 DR ALEXANDER BRUCE AND DR JAMES W. DAWSON ON 
Fig. 2. Uneven cylindrical appearance of the nucleated “tube”: the cell processes have joined in an 
imbricated manner and fused, and, with the fusion, the cell outlines have become lost. The discontinuous 
filament in each cell may now be traced as a continuous line. Cross-sections of such cylinders through 
nucleated and non-nucleated portions. 
Fig. 3. Contours of nucleated “tubes” have now become parallel, the sinuously-winding filament more 
marked, and the nucleus has become slightly peripheral and flattened, though still large and bulging into the 
“lumen” of the “tube.” Cross-sections of such ‘*tubes.” 
Figs. 4 and 5. Nucleated ‘‘tube” gradually assuming the characters of the fibres of a peripheral nerve 
with central filament very distinct, nucleus flattened and peripheral, condensed outer layer of myelin, and 
the appearance of a slight amount of interfibrillar tissue. 
Fig. 6. Isolated neuroma nodule, within the adventitia of a medium-sized vessel, lying in the anterior 
column of white matter (1st dorsal segment). The nodule is composed of interlacing fibres with neurilemma 
nuclei and the fibres are cut transversely, obliquely, and longitudinally. Note the central vessel and the 
outer thickened wall of the adventitia completely cutting off the nodule from the surrounding healthy white 
matter. Cf. fig. 19. Van Gieson’s stain. x 250. 
Vig. 7. Glia cell proliferation and hyperplasia in an area of commencing fibrosis in the cord. Note 
infiltration of lymphocyte-like cells, also the presence of spindle-shaped elements. Wan Gieson’s stain. x 350. 
Puate II. 
Figs. §-12. Cajal’s reduced silver method for myelinated axis cylinders. x 250. 
Fig. 8. Neuroma nodule. Whorl-arrangement of the fibres giving the typical ball-of-wool appearance ; 
some of the fibres interlacing in all directions and others passing parallel for a time. 
Fig. 9. Transverse section of normal small vessel in the white matter of the cord from neuroma case. 
Fig. 10, Similar vessel with delicate fibres in the adventitia. 
Figs. 11 and 12. Vessels in the grey matter of the 7th and 8th cervical segments showing within the 
adventitia a plexus of fine fibres, with branchings ending in homogeneous bulbs. 
Fig. 13. Anterior spinal root vessel within the pia (lumbar cord); showing very numerous newly-formed 
medullated fibres within the adventitia. Note the vesicular appearance and intertwining of the new fibres, 
that the internodal segments are short and irregular, the fibres being made up of elongated, often bulging, 
cylinders with narrow connecting bridges, and that the myelin stains specifically yet not so intensively as 
that of fully formed fibres. Kulschitzky-Pal and picro-fuchsin. x 350. 
Fig. 14. Cf. figs. 65, 66. Stages in the myelination of the nucleated “tube.” Note the segmental 
character of the tube in which the differentiation is taking place (a), the darkening (0), and the granularity (c) 
within the outer border of each segment; and the commencing lattice-work appearance given by the newly- 
formed myelin (d, e). Cross-sections of fibres in the above stages (f). Heidenhain’s iron-hematoxylin 
stain, x 700, 
Puate III. 
Figs. 15-18. Transverse sections at different levels of the lumbo-sacral cord. Note (1) numerous nodules 
both in the grey and white matter, (2) the unravelling of the fibres composing the nodules into the general 
texture of the tissue, (3) the radiating lines of fibrosis passing inwards along pial septa and lateral vessels, 
also (4) the marked fibrosis of the posterior root-entry zones. Paraffin sections. Van Gieson’s stain. Figs. 
15 and 16, x20. Figs. 17 and 18, x 10. E 
Figs. 19-22. Different varieties of nodules to show the intertwining of the fibres and the varying amount 
of neurilemma nuclei. Van Gieson’s stain, - 
Fig. 19. Isolated nodule in the white matter of the anterior column of the 1st dorsal segment. C/, 
fig. 6. x 180. 
Fig. 20. High-power view of the nodule in fig, 15 seen passing inwards from the pia in region of 
ligamentum deuticulatum. x 200. 
