168 GEORGE E. NICHOLLS 
was severed to form the delicate hinder wall to this new terminal 
chamber. The fiber seems to have flared out into a terminal plug 
in which several strands, one somewhat thicker than the normal 
fiber, can be distinguished. This les in contact with the menin- 
geal wall of this secondary sinus terminalis and was either just 
about to become attached to the meninges when the specimen 
was killed or, more probably, had actually made its new terminal 
attachment. 
5. It will now be convenient to consider more fully the con- 
dition of Reissher’s fiber in the subjects of eight experiments 
(3, 9, 19, 39, 46, 49, 55 and 70) which I have refrained from in- 
cluding in either of the four groups, although concerning most 
of them I have but little doubt as to which category they really 
belong. 
Thus in the case of no. 39 which was an experiment of. quite 
short duration, the sections show that, although broken by the 
experimental incision, the fiber has not retracted forward from 
the incision. Since the ray exhibited no reaction after the opera- 
tion, it is clear that we have a specimen which should be placed 
in the second of my four groups. During the dissection, however, 
a slip of the knife inflicted a cut far forward in the spinal cord. 
As the result of this post-mortem injury, a retraction of the fiber 
took place from before backwards and a simple spiral twisting 
has been produced which has affected the fiber back to the region 
of the incision. 
A similar accident occurred to no. 9 with a similar effect upon 
the fiber. In this case, however, the experiment had been one 
of considerable duration (11 days) and there had been manifested 
a well marked reaction. It is extremely probable, therefore, 
that in this specimen there had resulted the usual considerable 
retraction of the fiber which had, however, become straightened 
out before the specimen was killed. Reissner’s fiber is found in 
the sections extending fully to the point where the filum ter- 
minale had been severed and, in this resembling the condition 
of the fiber in no. 39, it is found twisted into a nearly continu- 
ous simple spiral (text-fig. 2). There can be little doubt that, 
but for the accidental breaking of the fiber after the death of the 
