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but into a Ringer’s solution, then it will bulge between the two 
points A and ZB on which it is hung, the apparatus being held 
horizontally. It is easy to understand that the gravitation brings the 
two points A and B closer to each other, but can never make them 
diverge. Consequently the gravitation will act against the dilatation. 
Notwithstanding this the muscle lengthens itself again. Owing to 
this observation we are able to record curves without the stretching 
weights, which always deform the curve, while we need not use the 
poisonous chloroform-benzene mixture. 
When it was once stated that a muscle is able to lengthen itself 
in Opposition to the gravitation, I tried if it would even be able to 
raise its own weight. I succeeded actually in seeing a muscle, placed 
vertically, fastened at the lower end, lengthen itself after contrac- 
tion. This fact had been observed some days before, but without my 
knowledge, by Dr. Bakers and Mr. Prakken, in this Laboratory. 
It being proved that cross-striated muscle tissue dilates actively, 
two new points of view have been opened : 
1. We are able to record curves, excluding all the forces which 
could deform it. | 
2. With the aid of this technique it will probably be possible to 
find a solution to the problem, raised by the result of my experiments. 
The question is: what intramuscular forces cause this dilatation and 
through which are they influenced? The dilatation may be caused 
by the perimysium externum, the sarcolemma, the sarcoplasma or 
by the fibrils. 
l can state at all events, that the perimysium externum is not able 
to cause the dilatation only by itself (by its elasticity), for even a 
fragment of muscle tissue, cut out by me, actually lengthened itself 
again. The sarcolemma, which is a homogeneous elastine-membrane, 
has a tendency to diminish its surface, in other words: to take the 
globular shape. 
Consequently it will never be able to lengthen the muscle. 
December 19th 1919. 
