SYMPATHETIC CELLS: ALBINO RAT 295 
Every one of the cells recorded in table 5 had an unbroken layer 
of Nissl granules around the two nuclei, and at: the middle of the 
cell there existed absolutely no trace of any partition whatsoever 
which might suggest the contiguous surfaces of two cells closely 
erown together. Figures 6 and 7 show the binuclear cells in a 
very young and in a comparatively old rat, respectively. 
If we determine, by direct measurement, the nucleus-plasma 
relation in this particular older cell (fig. 7), contrasting the volume 
of both nuclei with that of the cytoplasm, we find a ratio of 
1:5.0. This is almost as low as the ratio at birth, and indicates 
that we are dealing with an increase in the nuclear mass not 
accompanied by a corresponding increase in the cytoplasm. 
This, so far as it goes, is an argument against the suggestion that 
we have here two cells that are fused. 
According to table 5, the occurrence of binuclear cells is not 
related to sex. In many cases the numbers of these cells in both 
sexes are equal or almost equal. There appears, however, to be 
an increase in their number toward middle age, ranging from 
sixty days to 365 days, with a possible decrease later. 
Apolant found cells of the binuclear type in the superior 
cervical ganglion of an embryo rabbit three weeks old, and 
states that such cells persist in the older animal, when the cells 
have been completed anatomically and physiologically. Accord- 
ing to him, this is the result of direct nuclear division; about half 
of the binuclear cells being formed during embryonic life and 
the remainder later. It is not the purpose of this paper to deal 
with the function and origin of this type of celis. Their appear- 
ance in the postnatal stages of the rat, as recorded in table 5, 
agrees with what Apolant points out as the course of the develop- 
ment of the cells in the later ages of the animal. Carpenter and 
Conel (714) noted this type of cells in considerable number in the 
rabbit, guinea-pig, muskrat, and porcupine, but rarely, if ever, 
did they find them in the sympathetic ganglion of the rat. 
As these authors’ observations were made most probably on 
one or on only a few stages of the rat, the small number of such 
cells in the entire ganglion justifies their statement, in a way but 
nevertheless the presence of the binuclear cells in the superior 
cervical sympathetic of the rat is beyond question. 
