( 561 ) 
Difference 
Ringer’s sol. 
3.954 
3.544 
3.399 
Veratr. 1 : 5000 
3.954 
Nicotine 1:100 
3.510 
. CaClj 0.72% 
3.394 . 
0 
0.034 
0.005 
3.340 3.336 0.004 
Coffeine 1:100 
3.295 3.327 0.032 
In none of these cases was anything to be perceived of stiffness 
of the muscles. 
Therefore our results are perfectly in keeping with the opinion 
that the muscular fibre, when reacting upon a stimulus with a rapid 
contraction, works in quite another way than when it is brought in 
tonic contraction. In the first case it consumes non-nitrogenous matter, 
in the second it forms creatine, consequently consumes protein. 
Against the supposition of Grutzner that each of these actions should 
belong to a special kind of muscular fibres, tells among others our 
experience, that, with the rabbit, it is just the red muscles, which 
are distinguished for slowness in contraction, that contain less creatine 
than the white ones. Though the opinion of Bottazzi that muscular 
fibres show the phenomenon of tonus the more, as they are richer 
in sarcoplasma, as has already been pointed out by Mosso, is not 
quite in keeping with the observations, it may, however, especially 
after Engelmann’s important researches, be assumed that the rapid 
contraction is performed by the anisotrope elements, accordingly by 
the muscular fibrils. The seat of the tonus must therefore be sought 
in the sarcoplasma or perhaps in the parts of the fibrils between 
which the anisotrope elements find a place. In a further investigation 
into the two different kinds of contraction of the muscular fibres it 
will certainly be of importance to keep the attention also directed 
to the double innervation again demonstrated by Boeke. 
As to the starting-point of our investigation we think we are 
entitled to give an affirmative answer to the question whether the 
formation of creatine, and consequently the consumption of protein 
in the body, is largely influenced by the tonus of the muscles. 
Already many years ago it was proved by Peluger j ) of how great 
an importance the muscular tonus is for the production of heat. If 
our opinion is correct, it also follows from this that limitation in the 
supply of pro tein with the food, which is at the present day aimed 
b PflUger’s Archiv., Bd. XVIII, S. 247. 
