302 CHI PING 
In table 9 are given the amounts by which the cell diameters 
of the females differ from those for the males at four ages after 
eighty days. The mean excess for the females is about 6.9 per 
cent, which represents approximately an excess of 20 per cent 
in volume. When’ a corresponding comparison is made for the — 
diameters of the nuclei in these four groups, the average difference 
according to sex is feund to be zero. 
TABLE 9 
Showing, in four age groups, the absolute and percentage difference in the cell 
diameters of the largest cells in the superior cervical sympathetic ganglion of the 
female albino rat as compared with the male, based on the values in table 1. 
Because of the great difference in the body weights, the data for the growp at 250 
days are omitted 
CELL DIAMETER IN THE FEMALE DIFFERS FROM THAT IN THE MALE BY 
AGE 
Absolute u Percentage 
days 
80 —0.8 — 3.0 
124 210 + 9.6 
171 +3.9 +14.4 
365 +1.8 + 6.0 
INS SIN ae Oe ae RES RR ee Oe Cone oe ee =e (OY 
On the size of these cells in the inbred albino rat 
. To determine whether the size relations according to sex which 
have just been described for albino rats belonging to the so- 
called ‘standard strain’ are generally found, a series of inbred 
Albinos was examined, for comparison. 
The specimens used in this study were furnished by Dr. Helen 
D. King. - These rats had been closely inbred for thirty-four to 
thirty-five generations. Seven pairs were used, ranging from 
eighty-nine days to 154 days and each pair was from the same 
litter. The preparation of the specimens was made in the same 
manner as that for the series just described. 
The records on sex, age, body weight and length and the 
measurements of the cells and nuclei are given in the following 
table 10. 
