776 DR ALEXANDER BRUCE AND DR JAMES W. DAWSON ON 
course a degeneration which must be compared and related to the degeneration of the 
intra-medullary anterior nerve bundles in the cord. In addition to this, however, there 
was a definite proliferation of cells, many of which are spindle-shaped elements, which 
again fuse to form nucleated tubes, closely applied to one another and intertwining. 
Further, the fibrosis extended to involve these new-formed elements. Such a picture 
required very careful examination under oil-immersion and the use of several staining 
methods to interpret its constituent elements. Weigert and Bielschowsky preparations 
showed a disappearance of the myelin and a diffuse staining of the axis-cylinder of the 
emerging fibres, while control preparations, stained with Van Gieson’s method, proved 
that there is a dense network of new nucleated tubes and fusiform cells, and an 
advancing fibrosis which is causing their atrophy and disappearance. The appearance 
of some of these nucleated tubes is very similar to that which we have seen in stump- 
neuromata, where the increasing condensation of the scar-tissue causes compression 
of many of the new nerve tubes—the myelin of which does not yet take the specific 
myelin stain and shows as a homogeneous yellow zone with central axis-cylinder. 
Radiating from such areas may be found the nucleated tubes and spindle-shaped 
elements undergoing a fibrous transformation. 
* 
(6) PatcHes or Pure Fiprosis. 
This again must be brought into relation to a similar change in the spinal cord. 
It has already been stated that small areas may be recognised which, under low power, 
stain diffusely pink, and, under high power, reveal few or no structural elements. 
These areas are related to a thickened vessel, and:in the extension of the fibrosis the 
new-formed nucleated tubes are involved. Within those areas, showing no recognisable 
cell elements with other stains, there may frequently be found in Bielschowsky 
preparations diffusely-stained axis-cylinders which we have taken to represent the 
remains of axis-cylinders of the fibres displaced by the new-formed nucleated tubes. 
It is thus seen that the histological picture is an extremely complex and varied 
one, that at first sight the recognition of any relation between the different appearances 
is difficult, and that a prolonged investigation of serial sections and comparison of 
adjoining differently stained sections is necessary before any satisfactory conclusion 
as to the nature of these nucleated patches and nodules and their relation to one 
another can be reached. 
We look upon the patches showing a meshwork of interlacing fusiform cells, 
described in (3), as the first stage in a process which in the medulla and pons evolves 
as far as the nodule formations described in (4). Cells, the genesis of which cannot be 
traced, have proliferated, and the proliferated cells link on to one another and form 
chains of cells which converge to form parallel strands. The simpler strands, owing to 
