MULTIPLE NEUROMATA OF THE CENTRAL NERVOUS SYSTEM. 781 
In the medulla and pons the most distinctive feature of the formations was an 
interlacing meshwork. When this was analysed it was found to consist of fusiform 
elements and again nucleated tubes cut in various directions. In the protoplasm of 
many of the cells there was present on one side of the nucleus, or projecting beyond its 
poles, a deeply-staining filament which increased in size with the size of the cell. 
Further, many of these fusiform cells were found linked together by their adjoining 
processes which had fused, and stages could be followed in the transition to cylindrical 
tubes in which the fusion had become complete and the cell-boundaries had disappeared, 
and protoplasmic bands or tubes had resulted. In these nucleated tubes or protoplasmic 
bands there was present a deeply-staining central filament, winding in and out amongst 
the nuclei, and around it a homogeneous zone, with very numerous nuclei definitely 
within or projecting into the lumen of the tube. Further, it was noted that a cell-chain, 
thus formed, frequently divided into two, the first components of the chain lying very 
close, almost parallel to one another. The linked cells as they formed nucleated tubes 
tended to converge together to form strands, and in these strands of nucleated tubes 
running parallel to one another the central filament became gradually more distinct, 
the nuclei more flattened and peripheral and with an alternating position. Further, in 
such strands evidence was found of an undoubted commencing myelination, the tubes 
showing this all having a very definite segmental structure. Further, these parallel 
strands of nucleated tubes assumed a tortuous or twining character to form nodules, 
and during this further evolution the nuclei took a still more peripheral position and 
the whole tube more the character of a peripheral nerve. This was the furthest stage 
in the evolution of the nodules in the medulla and pons: the tubes had thus three 
phases in their evolution—firstly, a cellular one; secondly, that of protoplasmic bands 
or tubes; and thirdly, one showing the division into interannular segments and a 
commencing myelination. 
In the cord, therefore, we have well-stained nerve fibres, apparently terminating in 
nucleated tubes and fusiform cells; in the medulla and pons we have fusiform cells and 
nucleated tubes apparently forming strands of nucleated fibres which have many of the 
characters of the fibres forming the more fully evolved nodules in the cord but without 
their specific staining ; while the constituents common to the formations in both regions 
are the nucleated tubes and the fusiform cells. The position stated thus, it is not 
difficult to correlate the appearances, and the conclusion might at once be reached that 
in the cord we have simply a further stage in the evolution and differentiation of the 
fibres. 
Before, however, accepting this conclusion, it is necessary to ascertain if no other 
explanation can be found. If we limit ourselves to the cord and recall the fact that 
the nerve fibres composing the nodules could in all instances be traced to the immediate 
vicinity of the anterior roots, two possible explanations at once present themselves, 
both of which are in agreement with the old-established outgrowth theory. The one 
is, that the fibres represent aberrant anterior nerve roots in the sense of ORZECHOWSKI 
