SYMPATHETIC CELLS: NORWAY RAT 329 
By the aid of such a tabulation, there seems to be a chance 
to consider the possible influence of albinism, captivity, domes- 
tication, and inbreeding on the cells under discussion. 
The characters which may be compared in the several strains 
are: 
A. The morphology of the largest cells. 
B. Special cell forms (binuclear, pigmented, or vacuolated). 
C. The increase in the diameter of the cells from birth to 
maturity. 
D. The absolute size of the cells at different ages. 
E. The nucleus-plasma ratios. 
F. The rate of the formation of large from small cells. 
In making the comparison, the three strains will be briefly 
designated as ‘standards,’ ‘inbreds,’ and ‘Norway,’ and for 
convenience the values for the ‘standards’—which have been 
most completely studied—will be those to which the values for 
the other strains are referred. 
A. The morphology of the largest cells 
Figures 1 to 5 (Ping, ’21) show the morphology of the largest 
cells in the standards. In the other strains these cells have in 
general a similar appearance. However, it was: noted in the 
Norways that the Nissl granules were less segregated than in 
the standards. Whether this difference is correlated with albin- 
ism or domestication cannot be determined at present, because 
the Norways have not yet been domesticated. 
B. Special cell forms 
1. Binuclear cells. In the standards, binuclear cells were 
found in every ganglion examined (table 5, Ping, ’21) and the 
average number was 4.2 per ganglion. In the Norway they 
were found in only 54 out of 80 ganglia studied (table 6). The 
average number for the entire series of 80 ganglia was 2.2 per 
ganglion, and for the 54 ganglia in which they occurred, 3.3. In 
the Norways therefore, binuclear cells are less abundant. Again 
this difference cannot be correlated with either albinism or 
domestication. 
