22 JoURNAL OF COMPARATIVE NEUROLOGY. 
I type of Cells—This form of cell is represented by two 
varieties; one measures 77-175 ' in its long diameter, while 
the breadth is 43-86 4; the other measures 21-30 4 in its long 
diameter and the breadth is 12-25 4. The latterappears by the 
method in smaller numbers. This variety of cell receives the 
axone from II type of cells. The fiber of this I type cell divides 
into two branches, forming the ‘‘T’’ shaped fiber. These cells 
are those ordinarily called the ganglion cells. 
II type of Cells—The axone of such a cell breaks up with- 
in the ganglion into a large number of branches. The branches 
lose their myelin sheaths and terminate about the cells of I 
type, forming a pericellular basket. The second type receives 
the termination of axone from sympathetic ganglion cells. The 
cell-body measures 43-132 y in long diameter, while its breadth 
is only 30-55 p. 
Slight differences occur, however, as regards the morphol- 
ogy of these two varieties under Type I. The fiber of the 
larger cells is sheathed by medullary substance or myelin in all 
cases, while the fiber of the smaller cells is destitute of myelin 
except in a few cases. When the fiber is destitute of the my- 
elin sheath, the axone .shows a varicose appearance. These 
observations by Doaiet bear very directly on the suggestion of 
the writer that these small ganglion cells are not pathological, 
as has been maintained, but immature. For DocrEL here shows 
(1) that some of the small cells give off axones of the typical 
spinal ganglion forms; (2) that the axone is often unmedullated, 
itself sign an immaturity, and (3) finally that the number of 
these cells from which no axone is to be traced is large and 
hence these are not to be considered as functional at this stage 
of development. 
From these several observations, the writer concludes that 
the small cells of the spinal ganglion are in a growing state or 
in a more or less permanently immature condition. The grow- 
1 Tt is to be noted that the measurements of the spinal ganglion cells made 
by DocIeEt do not greatly exceed those given in Table II when the mean of the 
several diameters is taken. 
