PHYSIOLOGICAL EFFECTS OF LACK OF OXYGEN 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 

 (Fig. 123) was filled with pure oxygen. 

 A long glass tube a and a short one 

 b passed through the rubber stopper 

 in the bottle. The glass tube a was 

 connected with an Engelmann gas- 

 FIG. 121 chamber 7. 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 77. 

 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 

 was driven out of A through the gas- I 



chamber 7 by the flow of the water I 

 out of B, and the same amount of air 

 was suctioned through the gas- / 

 chamber 77 into t 1 '^ bottle B. In ; 

 this way the effecx of pure oxygen ..-* 

 could be compared with that of atmos- FIG ^' '' "' 



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- 



