AUTHORS’ ABSTRACT OF THIS PAPER ISSUED 
BY THE BIBLIOGRAPHIC SERVICE, FEBRUARY 28 
THE FIRST THORACIC WHITE RAMUS COMMUNICANS 
IN MAN 
S. E. JOHNSON anp M. L. MASON 
Anatomical Laboratory of Northwestern University Medical School! 
FIVE FIGURES 
In text-books of human anatomy and in current literature 
there is evident lack of agreement and uncertainty in the various 
statements regarding the occurrence of a white ramus com- 
municans in connection with the first thoracic spinal nerve. 
In Cunningham’s text-book of human anatomy (’18) we read 
that ‘“‘Each thoracic nerve, with the probable exception of the 
first, sends a visceral branch (white ramus communicans) to 
join the ganglhated trunk in the thorax.’ Piersol (’18) says, 
“from the first or second thoracic to the second or third lumbar.”’ 
In Lewis’ edition of Gray’s Anatomy (18) is this statement: 
“Two rami communicantes, a white and a gray, connect each 
ganglion with its corresponding spinal nerve.” According to 
Morris-Jackson (714), ‘““Each ganglion, with the possible exception 
of the first, receives a white ramus communicans from a thoracic 
nerve. . . . . The statement as worded does not commit 
the author as to the source of the white ramus which runs to the 
first thoracic sympathetic ganglion. It might come from the 
first, second, or third thoracic nerve, or even from the eighth 
cervical. In Poirier, Charpy et Cunéo (’08) we find the state- 
ment that the thoracic sympathetic ganglia are connected to 
the thoracic nerves by one or two rami communicantes. This 
statement is rather typical of the ones found in foreign texts 
generally. There is seemingly a desire to avoid statements 
warranting specific interpretation as to the nature of the rami 
which are described. It is quite obvious that the mere number 
of rami implies nothing as to their actual nerve constituents. 
1 Contribution no. 81, January 1, 1921. 
ae 
