336 CHI PING 
On comparing the diameters of the cells in the cerebral cortex 
of the rat, Sugita (18) found that those in the lamina pyramidalis 
and in the lamina ganglionaris of the Albinos were, respectively, 
4 and 7 per cent less in diameter than the corresponding cells 
in the Norway. 
In the foregoing instances it appears that there is a reduction 
in the relative size of the parts of the nervous system, as well 
as in some of the cell elements, in the Albino as compared with 
Norway. 
Incidental observations on captive Norways suggest that 
this reduction is the result of captivity or domestication. There 
remains, however, the difference in the relative weights of the 
spinal cord which occurs in the Albino, but is absent in the 
Norway, and in this instance it is possible that albinism plays 
a part. From these earlier observations we should have ex- 
pected to find the cells in the superior cervical sympathetic 
ganglion smaller in the Albinos. 
Contrary to expectation, these cells in the standards are 
larger than in the Norway, but also exhibit a sex difference, 
being larger in the females. Nevertheless, in the case of the 
inbreds, these cells are much smaller than in the Norways, and. 
show only a slight difference according to sex. At the moment, 
therefore, the size of these cells in the standards does not agree 
with the expectation based on the results obtained from other 
parts of the nervous system, but any simple interpretation is 
at once precluded by the very small size which they have in the 
inbreds. 
SUMMARY 
1. The growth of the largest cells in the superior cervical 
sympathetic ganglion of the Norway has two phases: (1) a com- 
paratively rapid growth from. birth to twenty-five days, (2) 
followed by a slow and gradual growth continuing to the end 
of the record. 
2. The growth of these cells in relation to body weight, body 
length, age, and the percentage of water in the brain does not 
show differences due to sex after the animal has passed puberty. 
