500 OTTORINO ROSSI 
It is not necessary to emphasize the chief result of these re- 
searches. Though in the birds sometimes it is not easy to iden- 
tify the ramus communicans by reason of its peculiar topographic 
relations, yet this is recognized clearly enough in the preparation 
from which is reproduced the first picture. Besides, I have met 
the same evidence in mammalian embryos. 
Supported by my findings, of which I have pictured the most 
evident, the results afforded by my studies may be summarized 
as follows: In embryos of birds and mammals there is demonstrated 
for the first time by direct anatomical observation the occurrence in 
the spinal ganglia of nerve cells the peripheral processes of which 
pass into the rami communicantes. 
In my own preparations there is no evidence which could 
demonstrate that these nerve cells have peculiar character or 
position. One could perhaps question the constancy of such 
findings. I do not believe that they are occasional because in 
thirty well-impregnated bird embryos I met them more or less 
clearly fifteen times, and in thirteen pig embryos six times. 
That previously illustrious investigators, such as Kolliker and 
Cajal, though successfully impregnating the processes, have not 
had the good fortune to impregnate their cells of origin, we can 
easily understand when we recollect all the circumstances which 
cooperate to modify the results of the wonderful method of Golgi, 
which is certainly able to give new and interesting findings about 
the relations of nerve cells when applied carefully and with suffi- 
cient persistence. 
Fig. 1 Cross-section of embryo of Passer sardoa. Golgi’s method. X 87. 
A spinal ganglion cell is seen sending its peripheral process into the ramus com- 
municans. #.c., ramus communicans; Sp.C., spinal cord; SP.G., spinal gan- 
glion; Sym.G., sympathetic ganglion. 
Fig. 2 Cross-section of embryo of Passer sardoa. Golgi’s method. 267. 
Three nerve cells of the spinal ganglion send their peripheral processes through 
the ramus communicans. Per.N., peripheral nerve; R.c:, ramus communicans; 
Sp.C., spinal cord; SP.G., spinal ganglion. 
Fig. 3 Cross-section of embryo of Passer sardoa. Golgi’s method. X 267. 
The spinal ganglion cell marked with a cross sends its peripheral process into the 
ramus communicans. One fiber of the anterior root (An.R.F.) divides at the 
level of the ramus communicans; one of the branches runs through the ramus 
itself. Other indications as in figure 2. 
