429 
3. 
The single instance of an advanced stage in regeneration was that 
of the dogfish (2) which formed the subject of the second experiment 
and which was allowed to live for sixteen days after the operation. 
Behind the incision the fibre had sprung violently and had shattered 
the sinus terminalis. Immediately in front of the incision, however, 
a new terminal sinus was practically complete. Here the cut end of 
the filum terminale had rounded itself off and, behind it, the meninges 
had grown together to enclose a space into which this secondary 
terminal neural pore opened freely (see the Text-figure). The fibre also 
ec. 
EN 9,9 9 8 
Pe re a 
os > = 
Seyllium canieula (2). Sagittal section through the secondary terminal sinus (s.t.) 
which has been formed at a point just anterior to that at which the experimental in- 
cision was made. (X 132.) c.c. canalis centralis. ep. ependyma. p.m. pia mater. 
Rf. REISSNER’s fibre. * * region of experimental incision. 
had, presumably by growth, become longer than the surrounding 
central canal, and its free end had come to lie against the hinder 
wall of the secondary sinus terminalis but had not, so far as I could 
determine, actually become attached. 
VIII. Conclusions. 
Notwithstanding the small number of experiments, I believe that 
such results as have been obtained, while not sufficient perhaps to 
furnish a decisive answer to the various questions set out above, do 
offer certain suggestions that are not without interest. 
In the first place, it would seem that breakage of the fibre brings 
about a temporary loss of control over the pose of the body when at 
rest and probably also when in motion. This would appear to afford 
definite confirmation of Drenpy’s theory of the function of the fibre, 
