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modified by Cox, whilst the brain was prepared directly in the liquid. 
For the control another mouse, not having been put under narcosis, 
was treated in the same manner. No differences whatever were to be 
observed in the microscopical preparations, obtained by’ means of the 
freezing-microtome. 
Neither did I observe any differences in the case of mice, injected 
in the manner used by Drmoor with repeated doses of morphia until 
death ensued. 
Thinking these results might have been impaired by the fact that 
the animals were decapitated only after death, I next tried with the 
utmost accuracy a repetition of the experiments of MANOUELIAN. 
A mouse was put into a turning cage, being therefore constrained 
to run incessantly, whilst the cage was kept in continual motion by 
means of a small motor driven by water. The motion was continued 
for four hours together, the animal experimented upon being therefore 
perfectly exhausted. Meanwhile the control animal had been kept in 
darkness, enveloped in wadding. The four hours having elapsed, 
both animals were very quickly decapitated, the heads being caught 
into the fixation-liquid, and the brain being further prepared in it. 
After ten weeks the preparations were impregnated with celloidine 
and section-series in frontal direction were made of both brains. In 
this way it became possible to obtain a comparable material. 
For further control another pair of mice was sacrificed, for the 
purpose of demonstrating by means of the method of Nisst the 
presence of the well-known modifications in the easily tinctured parts 
of the protoplasma of the nerve-cells. 
For whilst under normal conditions the elective tincturing part of 
the protoplasma of the ganglion-cells is divided into small granula, 
in case of fatigue these granula tend to dissolving more and more, 
the tineturing of the cellular body thus becoming homogeneous. 
These modifications are clearly to be observed in the ganglion-cells 
of the exhausted animal experimented upon: the fatigue therefore 
must have been exquisite. 
The preparations, made after the method of Gone! modified by 
Cox, offer however beautiful arborisations as well in the case of the 
non-fatigued animal, as in that of the exhausted one used for the 
experiment, the annexed photographical reproduction of the exhausted 
animal presenting no trace of retracted branchings, or of globular 
tumefactions, neither of being shaped like a string of beads. 
I have therefore not succeeded in demonstrating after this method 
modifications in the branching system of the nerve-cells of the cortex 
cerebi, caused by intense fatigue. 
