HuBER, Sympathetic Nervous System. 95 



Other writers, among whom may be mentioned Kolliker (41), 

 Lowit (42), Gescheiden (43), Retzius (44), Miiller (56) and 

 Dogiel (45), state that the ultimate fibrillae terminate on the 

 muscle cells. To throw, if possible, some new light on this 

 question, I have made sections, 5 /, in thickness, of the mus- 

 cular coat of the intestine of fishes, amphibia, reptilia and 

 mammals, previously stained in methylen-blue and then double 

 stained in alum carmine. In such preparations, when well 

 stained in methylen-blue, only the nerve fibers shov/ a blue 

 color, while the muscle cells are colored in the carmine. In 

 such sections, one may see the terminal branches of the sym- 

 pathetic neurons, in the inter-cellular cement between the 

 muscle cells; and it may be observed that all along, in their 

 course, they give off short and exceedingly fine branches, or 

 side twigs, which end on the muscle cells often near the nu- 

 cleus, in small terminal swellings of round, oval or pear-shaped 

 form. The terminal branches are always very varicose, and 

 after giving off a number of "side twigs" also end on the 

 muscle cells in the manner above described. This description 

 corresponds very closely to those given by Erik Muller (56) and 

 by Retzius (44), the latter having described an especially well 

 stained, Golgi preparation made from the bladder of a rabbit 

 9 days old ; the results obtained by the two methods being thus 

 corroborative. In Fig. 2, may be seen the ultimate ending of the 

 neuraxis of a sympathetic neuron on an involuntary muscle cell. 



A question of some importance in this connection is the 

 following — Do all of the muscle cells in involuntary muscle have 

 a distinct and separate nerve supply ? 



Retzius (44) gives no definite answer to this question, al- 

 though he inclines to the view that they do not. The answer 

 is difficult in so far as it is impossible to determine whether all 

 of the nerve fibers in a given preparation are stained. In pre- 

 parations in which this would seem to be the case, not nearly 

 all the muscle cells have a separate nerve ending. In the smooth 

 muscle of the intestine the varicose, intra-fascicular branches, 

 above referred to, have a more or less parallel course, and in 

 my most successful preparations, three to four rows of the 



