SOME EXPERIMENTS ON THE NATURE AND FUNC- 
TION OF REISSNER’S FIBER 
GEORGE E. NICHOLLS 
Beit Memorial Fellow 
Zoological Department, King’s College, London 
THIRTY-FIVE FIGURES 
CONTENTS 
ea linbrocduetyonmsy src eee RENO oir ois cok ie ores eR ete te os 119 
A. A review of the suggestions which have been made concerning 
the nature and function of Reissner’s fiber and the sub-com- 
TESTS OH RTH UO BTN Cie Ot On a ee 5 > co eR Oe eee ae 119 
B. Earlier attempts to determine the function of Reissner’s fiber 
by. expernimentalbmethods.: ..; . ister sces cs oan Blane oes 125 
C. An account of the present state of our knowledge of Reissner’s 
LT OVE Noha Big RG es ONES RS ok Uc eae ae Pe 128 
bi he scone of the present investigation. «conc... c.:-s6seds bass ome = 133 
PbeViaternalvand Methods. 5... i0h 8 ce. vo sae ee Me ieee Ona cede ees 136 
iY “Observations upon the living animals: . 2220432. 00.. eee ces dee ee 145 
V. A summary of the record of the experiments and an account of the 
MctecistUponyWeIssner SrHlO Or... 5.2.2 acs eae tata nel nee as Ciccks 149 
VI. The relation between the condition of Reissner’s fiber and the reac- 
POET ACY OVS(ey EV ot0 Nee REA Ais OI SERRE SB SRE oe >. RRP anaes a PR Reg ee Ae 166 
NM DS CHAS TOMm ree nt Piney remorse tnt corsga eet Moves exe rs- oeu ach CO hes BS inate vas 175 
1. The function and mode of action of the Reissner’s fiber ap- 
FOPN EG DES parece trie eh bs oh ann te Rent MRA AeA oie ag ka, Nk nena nn Raa 175 
2. The spiral winding of the fiber and the occurrence of ‘snarls’... 180 
3. The duration of the reaction and the problem of regeneration... 183 
ISD Pan SCLIN ATS AS ny ese eke eo ye Send 2 teas Wee Tee ns Satta a at 188 
Pe MMIMIGE TNLINGE CELLO Gs crane sad oe the ctre os kscheete ORE aK Ree ER os 190 
It is probable that concerning no part of the vertebrate ner- 
vous system have there been held views more widely divergent 
than those which have been entertained concerning Reissner’s 
fiber. 
In 1907, when I took up the study of this structure, Sargent’s 
‘optic reflex’ theory had met with very general acceptance. At 
an early stage in my work, however, I obiained proof that the 
117 
THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL. 27, NO. 2 
FEBRUARY, 1917 
