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through the reticular and post-central areas to the central or even para- 
central region. Along this band, aggregations of cells may be present in 
any part, most often post-centrally. Very few in the region of Clarke’s 
column. Inconstancy of their appearance a typical feature, as always. 
Medium and small-sized cells mixed, the more anterior being generally 
larger than the others. 
C 6. — See fig. 12, Plate I. — Cells, on the whole, abundant. In indi- 
vidual sections they may be few or many, scattered or grouped. Most 
numerous about junction of central and post-central areas (these two 
regions are not very distinct in the cervical enlargement). A small 
reticular group also common. More often, simply scattered cells in the 
other areas. There is a distinctly large proportion of big cells in this 
segment, not only anteriorly, but also more posteriorly, although here they 
are mingled with others, smaller and more rounded than polygonal in 
outline. 
C 7. — Cells abundant, especially along a broad band from the reticular 
angle to the central canal, but particularly, as in lower C 6, in the post- 
central areas. More often, just scattered cells anteriorly and in Clarke’s 
column areas, although there are often cells lying rather behind the region 
of Clarke’s column (posterior basal ?). No trace of any regular segmenta- 
tion. In size and shape the anterior cells are fairly large and polygonal, 
the central and post-central of large and medium sizes, the reticular and 
posterior basal medium-sized and more rounded. 
C 8. — See fig. 4 — Upper part as in C 7. In the lower, cells diminish in 
number and are more scattered, although small groups may be seen in any 
of the usual positions. In the lower, also, middle cells are more often seen 
lying between the anterior and lateral motor nuclei. In size they are much 
as in C 7. Cells are not more common in the reticular formation, nor is 
there any sign of segmentation or special grouping here. Very few cells 
in region of Clarke’s column. 
D 1. — Cells of the bigger type in base of anterior horn and (in upper 
part) between median and lateral motor groups. Medium-sized cells in 
central, para-central, and post-central areas, also in the formatio reticularis, 
also a few at the base of the posterior horn. Most abundant, and often 
persisting through a number of sections, just internal and a little anterior 
to the reticular angle, but never so closely packed as the cells of the inter- 
medio-lateral tract. The medium-sized cells individually closely resemble 
those of that tract, and sometimes it is impossible to say to which series 
any particular cell is to be allotted. Many of the post-central cells behind 
and external to Clarke’s column are of a smaller, more rounded type. 
