12, GEORGE E. NICHOLLS 
the ordinary (tecto-spinal) conduction paths through a number 
of neurons could be lessened in cases of urgency. 
Houser (’01) claimed that he had been able to confirm Sar- 
gent’s observations, while numerous observers seem to have ac- 
cepted Sargent’s theory concerning the function of the fiber. 
That, notwithstanding many weighty objections, this theory 
met with such general acceptance is doubtless to be attributed 
very largely to the fact that Sargent claimed (04) that his ob- 
servations had been fully confirmed by actual experiments upon 
living animals (vide infra). 
7. Although Sargent (03) was the first to describe the con- 
nection between Reissner’s fiber and the sub-commissural organ 
(his ‘ependymal groove’) he attributed comparatively little 
importance to this latter structure, asserting that it served 
merely as a support and anchorage for Reissner’s fiber. In this 
view he has been followed recently by Tretjakoff (13). 
K6lliker (02) recording the occurrence of Reissner’s fiber 
in the blind Proteus and other Amphibia, admitted that he had 
become convinced of the preformed nature of the fiber. He 
appears, however, to have been unable to choose between the 
conflicting views advanced by Studnicka, Sargent and Kalberlah. 
8. The work of Ayers upon ‘Ventricular Fibers in Myxinoids’ 
is of interest in that it contains the first suggestion that Reiss- 
ner’s fibers might be composed of numerous united delicate 
fibrillae springing from ependymal epithelial cells. Whether, 
however, he considers these fibrillae as of the same nature as 
the ependymal fibers which serve as supporting structures within 
the central nervous system, or not, Ayers does not make clear, 
and his work unfortunately contains a number of erroneous 
statements. He does not, indeed, refer to the fiber by name and 
appears to have been wholly unaware of previous work upon the 
subject. 
Thus, in Bdellostoma, he figures numerous more or less parallel 
ventricular fibers which, while they may perhaps represent 
several lengths of a much folded and snarled fiber, may equally 
well represent some artifact. It certainly is not the normal 
condition in this animal. Moreover, it would appear that 
