(27. 
which point the nodal curve passes, just as with a torsal line of the 
second kind; and indeed the plane 2 through d contains besides d only 
twelve generairices of 27°, intersecting each other mutually in 
1.12.11 = 66, and d in 12 points counting double, which amounts 
together to 66 + 24—90 points of the nodal curve; so one is 
missing, but is the point of intersection in a closer sense of the two 
generatrices coinciding in d, and according to the above this cannot 
lie on /. In passing we learn from this consideration that the nodal 
curve of 2*° touches each plane through l and either a torsal line of 
the second kind or a double edge in twelve points lying either on that 
torsal line or on that double edge. 
That a double edge, however, does not bear itself altogether as a 
torsal line follows from a repetition of the above given consideration 
‘with the three planes 2,, 2, 2,; for now in 4, as well as in 4, two 
real generatrices of £2?’ will lie. Nevertheless the nodal curve has 
here with @* not only a contact by two points, but even one by 
three points, so that the plane of osculation of the nodal curve 
coincides with the tangential plane of 2%, and the nodal curve touches 
one of the two branches of the section of @* lying in the tangential 
plane. 
Indeed, it is clear that besides the 368 + 80 + 58 — 506 points 
of intersection already found no others are possible than the 6 points 
on the double edges, which occupy us here; for each point of inter- 
section not lying on / must be the point of contact of a generatrix 
of 2° with a conic of @*, so a pinchpoint of a torsal line of the 
second kind, or of a double edge; as there are 6 of the latter sort 
in evidence and 524 — 506 = 18 points missing, each of those six 
points must be counted three times. 
Physiology. — “The posterior longitudinal fascicle, and the manege 
movement.” By Dr. L. J. J. Musxens. (Communicated by Prof. 
C. WINKLER). 
(Communicated in the meeting of October 26, 1912). 
In a series of experiments in cats by means of different needles 
a lesion was caused in the cerebro-spinal axis, between the posterior 
commissure and the vestibular nuclei, avoiding the V-vestibularis, of 
which the lesion invariably causes such vehement rolling movements 
to the side of lesion, that the observation of the manege-movements 
is impossible. The microscopical control of the lesion and its results 
was performed after the method of Marcur, 
