762 DR ALEXANDER BRUCE AND DR JAMES W. DAWSON ON 
which tends to cause considerable confusion (fig. 7). The young fibroblasts are in 
appearance very similar to the fusiform cells which arise from the terminal ramifications 
of the nucleated tubes, especially as the latter undergo a fibrous transformation. 
Ganglion Cells.—To a remarkable extent the ganglion cells were preserved in the 
grey matter, which had not been encroached upon by the fibrosis advancing from centre 
and periphery. The majority of the cells were altered in character, but many 
apparently healthy cells were present. In other sections few of the cells failed to 
show changes: chromatolysis in all stages, from a slight central or peripheral removal 
of Nissl’s granules to their entire absence, vacuolation of the cytoplasm (fig. 50), 
eccentric position of the nucleus, and all stages of atrophy of the cells. A few cells 
were found which, even with very complete differentiation, showed a diffuse staining 
and fusion of the granules. 
Throughout the whole dorsal cord below the 3rd dorsal segment, this fibrosis is 
present to a greater or less extent. Sections at various levels show that the central 
canal is involved and that the change has extended to the commissural vessels on 
either side, thence to the centre of each grey matter, from there has passed forwards 
to the anterior horn, outwards to the lateral horn, and backwards to the posterior. 
When this fibrosis was very marked the grey matter in Weigert-fuchsin sections was 
picked out in pink. In the adjoining lateral and in the posterior columns there was a 
varying degree of sclerosis with markedly fibrosed vessels. The posterior columns 
showed also a striking degree of fibrosis in the posterior root-entry zones. From this 
severe degree of involvement of the grey matter there were all transitions to the 
sections which showed only a slight nodule formation and only a trace of commencing 
fibrosis. 
It is when we reach the second lumbar segment that the probable sequence of the 
processes becomes evident. Weigert-fuchsin sections at this level (figs. 51 and 52) 
show on both sides finer or thicker fibrous strands passing from the periphery of the 
cord to the borders of the grey matter, there to expand into a loose meshwork of 
pink-stained fibres and not involving to any marked extent the grey matter, the cells 
of which stand out clearly. In the formatio reticularis, on one side, there is a very 
evident area of fibrosis, with the remains of a nodule, the connections of which with 
the periphery can be traced even in the thickened lateral vessel. On the opposite side 
(fig. 52), a dense area of fibrosis occupies the base of the anterior horn, stretches 
amongst the antero-mesial group of cells and laterally to the postero-lateral group, 
where the remains of a whorl of fine fibres may still be recognised. Pial septa and 
vessels throughout the segment show a very marked thickening. 
Similar changes are present in relation to all the nodules throughout the lumbo- 
sacral cord, the variations depending on the extent and distribution of the fibrosis. 
A symmetrical involvement of the grey matter on opposite sides is frequent, and a — 
similar symmetry has been noted in relation to the lateral columns, which were often — 
mapped out by fibrous strands. In the 3rd lumbar segment, the markedly thickened — 
