x 
FURTHER EXAMPLES OF THE PROLONGATION OF THE 
LIFE OF THE EGG BY LACK OF OXYGEN 
1. It is rather curious that lack of oxygen, or probably the 
suppression of cell division, should be able to delay the disinte- 
gration with which the egg of the sea-urchin is threatened after 
artificial membrane formation. We found an explanation for 
this phenomenon in the fact that the process of nuclear or cell 
division is critical for the egg in danger of disintegration. If 
one suppresses this process the disintegration is markedly 
retarded. The cell division can be suppressed or retarded by 
the suppression of oxidations as well as by narcotics. We also 
called attention to the fact that if we allow normally fertilized 
eggs to segment in abnormal solutions, the process of cell divi- 
sion is also accompanied by processes of disintegration (droplet 
formation) comparable to those which are characteristic for the 
egg after artificial membrane formation. We should therefore 
have aright to expect that if we put fertilized eggs into abnormal 
solutions, their lives will be prolonged if we inhibit cell division 
either by lack of oxygen or by KCN or by other means which 
inhibit cell division, e.g., narcotics. We should also logically 
be led to suppose that unfertilized eggs will live longer in such 
abnormal solutions than fertilized eggs, sunply for the reason 
that they are not threatened with nuclear or cell division. 
The writer has made a series of observations which show 
that quite generally unfertilized eggs suffer less in abnormal 
solutions than fertilized eggs; and that fertilized eggs suffer 
less rapidly if their oxidations are suppressed. 
1 The narcotics suppress or retard the process of cell division and development 
without diminishing the rate of oxidation in the egg noticeably. Loeb and Waste- 
neys, Jour. Biol. Chem., Vie OLS OLS: 
85 
