AFFERENT PATHS OF SYMPATHETIC SYSTEM 499 
would tend to clarify the relations of these fibers to their cells 
of origin by means of direct anatomical findings. In accordance 
with these conclusions, I find it interesting to report the follow- 
ing results which, after long work, I was able to reach by Golgi’s 
method in successfully impregnated specimens. 
Series I. Findings in bird embryos by the rapid Golgi method 
Figure 1 reproduces a part of a cross-section of an embryo of 
Passer sardoa near the time of hatching. We see a bipolar 
cell of a thoracic spinal ganglion (SP.G.) sending its peripheral 
process into the ramus communicans (R.c.), where it can be 
traced as far as to a formation which by its position, characters, 
and presence of a multipolar nerve cell we can easily recognize 
to be a sympathetic ganglion (Sym.G.). 
In figure 2 is reproduced, from a cross-section of the thoracic 
part. of an embryo of Passer sardoa, the anterior lateral region 
of the spinal cord (Sp.C.) and a spinal ganglion (SP.G.). In 
the spinal ganglion three nerve cells (the more darkly pictured) 
are to be found which send their peripheral processes into the 
ramus communicans (R.c.), while two other cells (drawn more 
lightly) send their processes towards the peripheral nerve (Per.N.). 
The same evidence is to be seen in figure 3 and concerns one 
of the three nerve cells stained by Golgi’s method (the one marked 
with a cross). In this preparation another interesting finding 
appears: one fiber (An.R.F.) of the anterior spinal root divide 
at the level of the ramus communicans (R.c.) and sends one branch 
into the ramus communicans and the other into the peripheral 
nerve (Per.N.). Another spinal ganglion cell sending its pe- 
ripheral process into the ramus communicans is reproduced in 
figure 4. 
Series II. Findings in pig embryos by the Golgi method 
Figure 5 reproduces part of a cross-section of one embryo. 
One spinal ganglion cell (SP.G.) is clearly seen sending its pe- 
ripheral process through the ramus communicans (f.c.) as far 
as the sympathetic ganglion (Sym.G.).. Another nerve cell 
sends its peripheral process into the peripheral nerve (Per.N.), 
where it meets the fibers of the anterior spinal root. A similar 
finding is to be found, under greater magnification, in figure 6. 
