PHYSIOLOGICAL EFFECTS OF LAOK OF OxyYGEN 395 
the consumption of oxygen is, within wide limits, independent 
of the partial pressure of the oxygen, and that it makes nor- 
mally little difference for the processes of oxidation whether 
we breathe air or pure oxygen. Still, in order to determine 
experimentally the action of pure 
oxygen upon cleavage, I made the 
following experiments. 
) An inverted ten-liter bottle A 
a Pes (Fig. 123) was filled with pure oxygen. 
; A long glass tube a and a short one 
0 b passed through the rubber stopper 
in the bottle. The glass tube a was 
connected with an Engelmann gas- 
EGE chamber I. The short glass tube b 
was connected with a longer tube c, and the bottle B was 
filled at the beginning of the experiment with water. A 
second short glass tube passed through the stopper of the 
latter and was connected to the Engelmann gas-chamber IJ. 
The connecting rubber tube between A and B was filled 
at the beginning of the experiment with water and closed 
by a pinch-cock. As soon as the 
pinch-cock was opened the oxygen oe 
was driven out of A through the gas- 
chamber I by the flow of the water ) 
out of B,and the same amount of air “On, 
was suctioned through the gas- Fs 
chamber II into t’~> bottle B. In} 0 : 
this way the effect vf pure oxygen + : 
could be compared with that of atmos- a, Pe a 
pheric air. A few important but self- 
evident details in the arrangement of the experiment have 
been omitted in the drawing. 
In one experiment eggs which had been in the eight-cell 
stage, but the cleavage-cells of which had been fused by ex- 
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