d 
THORACIC TRUNCUS SYMPATHICUS 417 
There seems also to be a rather large number in the first 
thoracic ramus. The upper two thoracic rami are also charac- 
terized by the presence of fibers as large as 13, which are usually 
absent from the others. 
Fig. 3 Tenth thoracic white ramus of the cat with associated gray fascicles. 
There was a large separate gray ramus not shown in the figure. Osmic acid. 
X 425. 
Bidder and Volkman ‘(’42) were the first to consider these 
larger fibers as sensory. Langley (’92 a) found difficulty in 
correlating the degree of sensitiveness of different parts of the 
sympathetic system, as evidenced by the ease with which their 
stimulation would produce general reflexes, with the number of 
THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL. 29, No. 4 
