Hatat, Spznal Ganglion Cells in the Rat. 5 
from cervical enlargement) is quite variable ranging from 5546 
yw to 19x17 , in diameter. The following table shows the size 
of the cell-body and its nucleus respectively : 
TABLE I—Showing the size of the spinal ganglion cells in the cervical gan- 
glia of the adult white rat. 
eries A 
Cell-body Nucleus Cell-body Nucleus 
51x50 19X15 56x40 18X15 
60x 48 15X15 58X45 18X16 
56X47 17X15 59X50 18X15 
55X35 19X15 55X50 16X16 
50X50 20X15 50X45 19X15 
Average size 55x46 18X15 
Series a 
34X31 14X14 36X 33 16X15 
39X28 15X13 30X 26 15X12 
44 X 34 14X16 42X 31 15X14 
40X25 17X15 40X 34 17X15 
Average size 38X25 I5X14 
Series B 
30X 24 13X11 25X25 14X13 
26X25 L2>CrZ 25X20 I2X II 
25X24 Ie hie ; 
Average size 26 X 23 je 3>.< 17> 
Series b 
19X15 1oX 9 19X15 IoX10 
19X19 10X10 19X15 IIX 9 
20X19 11X10 
Average size 19X17 10X10 
Series A.—Measurements of largest cells, two from each 
section, taken from five successive sections, 6 to 7 , thick. 
Series a.—Measurements of cells next in size to the largest. 
Two cells in each case from the same sections used for Series A. 
Series B.—Measurements of cells next in size to Series a. 
One cell in each case from the same section used for Series 
AG, a 
Series b.—Measurements of smallest cells. One cell in 
each case from its same section used for Series A, a, B. 
There is also a third group of cells which we shall desig- 
nate Series C. This contains two kinds of cells in size, one 
being nearly the size of those in Series a, and the other the 
