THE FUNCTION OF REISSNER’S FIBER 189 
6. The time required for regeneration is probably not less 
than a week, even when the retraction has not been extensive 
and the filum terminale and sinus terminalis are undamaged; 
in the case of the experimental material probably several weeks 
are required. Regeneration commences with the uncoiling 
of the fiber, which may be complete in a couple of days. The 
fiber extends backwards more or less slackly, becomes less swollen 
and probably by further growth, comes once more into contact 
with the hinder wall of the sinus terminalis (original or second- 
ary) into which 1t becomes inserted. 
7. It would appear, therefore, that, as suggested by Dendy, 
the fiber serves to control automatically the flexure and pose of 
the body. While it is probable that the related sensory cells 
are largely concentrated in the sub-commissural organ, it is 
equally probable that many other such sensory cells are scattered 
in the ependymal epithelium of the canalis centralis throughout 
the length of the spinal cord. 
