The hydrogen-ion concentration and oxidation-reduction potential of the cell-interior before and after fertilisation and cleavage: A micro-injection study on marine eggs

In our previous communications on this subject we have described experiments dealing with the micro-injection of indicators into single cells. In the conclusion to our paper (10a) on the pH. and rH of the Amœba, we said, “It is hoped that other biological data will soon be available . . . such problems as the . . . oxidation-reduction potentials of egg-cells before and after fertilisation at once present themselves.” The present paper is devoted to these problems. Warburg (17) and Meyerhof (8), and afterwards other workers, observed an enormous increase in the oxygen-consumption of the egg to take place on fertilisation. Shearer (12) found that this occurred at the moment of contact of the spermatozoon with the egg membrane. In view of the fact that the increase was about 2000 per cent., it was clearly a matter of great interest to determine whether the rH changed at the same time. We have attempted to follow the changes in rH by micro-injection experiments and by staining. The two methods failed to give concordant results for reasons which are discussed in the text.