THE CERVICAL SYMPATHETIC TRUNK 339 
The constituent fibers of this plexus stain rather heavily with 
silver and range in color from hght brown to black. They also 
vary greatly in size, the smallest being perhaps not more than 
one-eighth the thickness of the largest. The larger axons can 
often be seen to branch, but the smaller ones seem to run for 
ae 
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Fig. 10 Intercellular plexus in the ganglion cervicale superius of the dog. 
Section 204. Pyridine silver.  X 800. 
considerable distances without branching. The majority of the 
fibers are very fine. They run in and out among the cells, twist- 
ing and turning, crossing and recrossing and forming together 
a dense interlacement. That practically all of these fibers are 
unmyelinated can be seen at once by comparing such a prepara- 
