40 HUBER. [Vol. XVI. 



sheath at some distance from the cell body ; thus for the first 

 time pointing out conclusively its nervous nature. 



The true nature of the spiral fiber and the network, which 

 had been described by some of the earlier investigators, and 

 their relation to the protoplasm and the straight process of the 

 cell, were, however, not understood until Ehrlich's methylene 

 blue method became known. Ehrlich (i8), in his first communi- 

 cation on the reaction of methylene blue on living nerve tissues, 

 gives a very clear description of the spiral fiber and network. 

 I take the following brief account from this article: "The 

 spiral fiber, which alone was stained blue, divides into fine 

 fibrillae, which unite to form a network, which network may 

 enclose the entire cell or only a portion of the cell. From this 

 network fine fibrillae are given off, which end on the cell in 

 small terminal swellings. This mode of ending of the spiral 

 fiber was observed in all the larger ganglia examined ; also 

 in the smaller ganglia found in the heart, bladder, lung, and 

 pharynx." The fact that the spiral fiber was medullated led 

 Ehrlich to believe that it was a cerebro-spinal fiber, and that 

 its course was centralward, and to express the opinion that it 

 conveyed impulses from the nerve centers to the sympathetic 

 ganglia through the network about the cell. Ehrlich's obser- 

 vations were soon corroborated by Aronson (19), and by Arn- 

 stein and his pupil Smirnow. In the account given by Arnstein 

 (20) the network formed by the end branches of the spiral fiber 

 is described as a closed one ; the terminal fibrillae mentioned 

 by Ehrlich and Aronson were only occasionally seen, and then 

 only when the network was imperfectly stained. Arnstein 

 states that they found it extremely difficult to determine which 

 direction — centralward or toward the periphery — the spiral 

 fiber takes on leaving the cell ; often it was impossible to 

 decide. In the sympathetic cells found in the pharynx of the 

 frog, the spiral fiber went to the periphery, often branching in 

 its course. Retzius (21), in a short but very comprehensive 

 account of his observations on methylene blue stained sympa- 

 thetic ganglia of the frog, adds a number of details to obser- 

 vations previously made. He here points out that the terminal 

 network of the spiral fiber is always within the capsule of the 



