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MULTIPLE NEUROMATA OF THE CENTRAL NERVOUS SYSTEM. 773 
to one another, end to end, their processes fuse in an imbricated manner, and that by 
the time the cell-chain thus formed is extricating itself, as it were, from the maze of 
cells and passing out from them, it has assumed an uneven cylindrical appearance, the 
points of fusion being still narrower in calibre than the parts of the cylinder which 
contain the nuclei. Such nucleated, protoplasmic cylinders are, in future, indicated 
when the term “ nucleated tube” is used. 
Several of these chains of linked cells give the appearance of a dichotomous division 
(figs. 59 and 60). This forking in some instances clearly reveals the mode of origin of 
the two first components of the branches, for the first links in the respective new chains 
lie very close and almost parallel to one another. The impression is received that a 
longitudinal cleavage of a terminal cell had occurred, that the proximal portions of each 
resultant cell had remained attached to the common stem, and that growth in length 
had continued in each new branch till, further on, a new longitudinal cleavage had 
taken place when a new dichotomous division resulted. No mitosis could anywhere 
be noted. 
The convergence of the nucleated tubes forms bundles which run as parallel strands 
for a varying distance (fig. 62), and then assume a more convoluted course. Such 
convoluted nucleated tubes (fig. 63) form the transition to the definite nodules to be 
described below (4). 
Between the parallel strands formed by the convergence of the cell-chains are found 
cells and tubes cut transversely, which show clearly their identity with the longitudinal 
elements. 
Structure of the fusiform cells and nucleated tubes.—The earliest stage of the cell 
is a very thin spindle, with an elongated nucleus and a slight amount of protoplasm 
extending from its poles. As the cell increases in size the protoplasm extends, and 
with Van Gieson’s stain is homogeneous and faintly tinged pink. Larger cells, under 
oil immersion, reveal the presence of a more deeply staining filament in the protoplasm 
just on one side of the cell; this filament extends, with the growth of the cell, beyond 
the poles of the nucleus and becomes more evident. In cells which show a central 
nucleus, their filament can often be recognised through it and extending on either side 
for a short distance. The nucleus stains always deeply, but shows a chromatin network 
and membrane and fine nodal points, one or two of which are always larger than the 
others. The transverse section of such fusiform cells shows the nucleus at first occupy- 
ing almost the whole disc ; later it leaves a portion of protoplasm on one side, in which 
is again recognised the deeply-staining point (fig. 1). 
As the cells become linked to form chains, the central filament becomes more 
evident in each cell element, and as the fusion of the imbricating processes becomes 
complete and the cell borders disappear, the discontinuous filaments form a continuous 
line which may be traced passing two, or three, and even more nuclei. The surround- 
ing protoplasm in these tubes is homogeneous, yellow tinged with faint pink, and its 
outer border is often denser and deeper pink. ‘The nucleus tends to be peripheral, but 
