[HuBER, Scnsofv Nerve-fibers in Visceral Nerves. 137 



lated fibers 7.2 ^i to 9 ^^ in diameter ; the latter he calls large 

 sympathetic fibers. He finds no fibers of intermediary size be- 

 tween these two extremes, belonging to the sympathetic, but 

 describes medullated vagus fibers 4. 5 /^ to 6. 3 ;< in diameter, 

 which he calls large vagus fibers, and assumes that when med- 

 ullated fibers of this diameter are found in the sympathetic, 

 they come from the vagus. As the observations of Edgeworth 

 were at variance with these recorded by Langley (3), the latter 

 in a short communication in defence of his investigations, points 

 out numerous errors in the work of Edgeworth (4). Of these 

 errors it will suffice to refer only to the ones, to which atten- 

 tion is drawn in the following statement of Langley (5), which 

 has reference to the large vagus fibers and their distribution : 

 "This assumption is unfounded, since medullated fibers of 

 4. 5 ;/ to 6.3// in diameter are present in the sympathetic in 

 situations where there can be no question of any admixture of 

 vagus fibers." The foregoing quotations show clearly that the 

 investigators mentioned were able from data obtained from the 

 measurement of nerve fibers found in cross sections or in teased 

 preparations of white rami and sympathetic nerves fixed in 

 osmic acid, to reach the conclusion that two distinct varieties of 

 medullated nerve fibers were to be found in the visceral nerves 

 — very small ones, varying in size from about 2^ to 3/^ in 

 diameter and larger ones from about 4. 5 // to 12^ in diameter. 



That the smaller medullated nerve fibers above mentioned 

 are the white rami nerve fibers has been abundantly shown by 

 the physiological experiments of Gaskell, Langley, Sherring- 

 ton and others, which have been confirmed by histological ob- 

 servations ; that the larger medullated fibers are afferent fibers, 

 it is my purpose to emphasize. 



Concerning the white rami fibers — preganglionic fibers — it 

 is my purpose to speak very briefly, since numerous observers 

 who have studied the sympathetic ganglia and their nerve 

 roots have called attention to the fact that these fibers terminate 

 in the sympathetic ganglia in intracapsular end-baskets which 

 enclose the cell bodies of the sympathetic neurones, and this 

 not only in the chain ganglia, but also in the prevertebral and 



