758 DR ALEXANDER BRUCE AND DR JAMES W. DAWSON ON 
regenerate new fibres. If this degeneration ascend to the point where the neurilemma 
sheath is lost, the new fibres tend to stray into the pial spaces and vessels and to form 
neuromata, instead of passing onwards in the old sheaths of Schwann to form leashes 
of young fibres in the degenerated tube. 
A careful examination of the cord throughout its whole extent has proved the 
almost entire absence of any degeneration in the extra-medullary portions of the 
anterior nerve roots. The nerve roots were retained in most of the segments, especially 
in those in which the nodules were most numerous, and the pial fibres emerging 
laterally and medially from the vicinity of the emerging zone were in no way 
associated with an extra-medullary retrograde degeneration arrested at the point 
peripheral to the Ablassungzone. A regenerative process, in the sense of NAGEOTTE’S 
findings in tabes, can, therefore, not be assumed as an explanation of the pial fibres. 
In only one funiculus of the extra-medullary anterior roots was an appearance 
noted which might be interpreted as a regeneration of new fibres within the old 
sheaths of Schwann: this passed through several successive sections. It must, 
however, be stated that the radicular portion of the root was not examined, but, were a 
retrograde degeneration to be accepted as an explanation of the new pial fibres, it must 
of necessity have extended to the Ablassungzone and been evident in the retained 
roots. It must further be mentioned, ere leaving this question of the relation of the 
precise point of origin of the abnormal pial fibres, that the intra-medullary portion 
of the anterior roots frequently showed a myelin degeneration. This process was 
secondary to the fibrosis accompanying the nodule formation and will be referred to in 
a later section. 
(d) Distribution of the Neuromata. 
It has already been noted that with the exception of the upper five cervical and 
the 2nd and 3rd dorsal segments, no part of the cord was free from nodule 
formation. ‘The first indication of such in the 6th cervical segment occurred as a 
very small nodule in relation to a vessel of the anterior roots. The few fibres com- 
posing this nodule could be traced in serial sections to fibres passing in from the 
periphery along this vessel, and in subsequent sections the nodule broke up into fibres 
within the general substance of the grey matter. The normal structure of the white 
and grey matter was retained, but at the postero-lateral angle of the anterior horn a 
slight amount of fibrosis indicated that nerve fibres had been present: under high 
power this was confirmed, as ghost-tubes could be distinctly recognised as nerve fibres. 
In the opposite horn, at each angle, antero-mesial, antero-lateral, and postero-lateral, 
a similar change had evidently occurred, and the vessels leading to these points from 
the periphery showed a commencing fibrosis. It was evident that fine fibres had 
passed, in the adventitia of these vessels, to the angles of the grey matter and had 
there broken up, to disappear finally with the onset of the fibrosis. With the 
exception of this very minute nodule and the indications that other abnormal fibres 
