No. I.] SYMPATHETIC GANGLIA OF VERTEBRATES. 73 



nomena, such as peripheral reflexes, etc., which have been 

 observed in the sympathetic system. My own observations, 

 based almost entirely on sections, do not give me sufficient 

 evidence on which to judge these interesting and, if corrobo- 

 rated, most important observations which Dogiel has given 

 us. Cells with long, slender processes, such as he has described, 

 have now and then been seen by me, but I have not been able 

 to trace these processes for any distance. I may, therefore, 

 dispense with any further discussion of these so-called sen- 

 sory sympathetic cells. 



Non-Mediillated and Mediillated Nerve Fibers in the Sympa- 

 thetic Ganglia. — In sections of sympathetic ganglia stained in 

 methylene blue, smaller and larger medullated fibers and non- 

 medullated fibers may be seen between the ganglion cells. 

 These have been observed by Kolliker, Ramon y Cajal, Len- 

 hoss6k, Sala, Van Gehuchten, and others, in Golgi preparations 

 of the sympathetic ganglia of Mammalia, and by Aronson and 

 Dogiel in methylene blue stained preparations of these struc- 

 tures. In serial sections of the chain ganglia removed with 

 the white rami, stained in methylene blue, bundles of medul- 

 lated fibers may readily be traced from the white rami into the 

 ganglia, although it is not always easy to trace individual fibers 

 for any long distance. In the ganglia such medullated fibers 

 are seen branching into two or three branches, which may or 

 may not be medullated, and in a number of instances such 

 branches were traced to a sympathetic cell, where, after further 

 branching, they terminated in a pericellular plexus which sur- 

 rounded the cell body of the sympathetic cell. In well-stained 

 preparations such pericellular plexuses are easily found, although 

 in sections it is not always easy to connect such plexuses with 

 any particular nerve fiber. These pericellular plexuses vary 

 much in complexity and in the arrangement of fibrils which 

 form them. They may be very loosely woven, or, again, made 

 up of a large number of fibrils. The fibrils may be quite smooth, 

 or show numerous and large varicose enlargements. The ones 

 shown in PI. V, Fig. 23, a small portion of a section of the 

 stellate ganglion of a dog, stained in methylene blue and alum 

 carmine, may be looked upon as presenting the general appear- 



