CONDITIONS OF CELLULAR IMMORTALITY 53 



sion and further development. The latter processes may 

 be regarded as inhibiting or modifying the mortal pro- 

 cess. Loeb and Lewis' undertook experiments, based 

 upon this view, to see whether it would be possible by 

 chemical treatment of the egg to prolong its life. Since 

 in general specific life phenomena are perhaps, on the 

 chemical side, chiefly catalytic phenomena, it was held 

 to be reasonable that if some substance could be brought 

 to act on the egg, which would inhibit such phenomena 

 without permanently altering the constitution of the 

 living material, the life of the cell should be considerably 

 prolonged. The first agent chosen for trial was potassium 

 cyanide, KCN. It was known that this substance weakened 

 or inhibited entirely a number of enzymatic processes in 

 living material, without materially or permanently alter- 

 ing its structure. 



It was found that, normally, the unfertilized egg of the 

 sea-urchin would live in sea-water at room temperature, 

 and maintain itself in condition for successful fertiliza- 

 tion and development, up to a period of about twenty-three 

 hours. After that time the eggs began to weaken. Either 

 they could not be successfully fertilized, or if they were 

 fertilized, development only went on for a short time. 

 After 32 hours, the eggs could not, as a rule, be fertilized 

 at all. The experiment was then tried of adding to the 

 sea-water, in which the unfertilized eggs were kept, 

 small amounts of KCN in a graded series, and then exam- 

 ining the results of fertilizations undertaken after a stay 

 of the unfertilized eggs of 75 hours in the solution. It 

 will be noted that this period of 75 hours is more than 

 three times the normal duration of life of the cell in 

 normal sea-water. The results of this experiment are 

 shown in summary form in Table 4. 



