22 



LOGARITHMIC ORDER OF DEATH 



and the probability that n cells are dead is 



p»=[i-(w)'T 



If the tadpole is dead when n brain cells are dead, 



Pn 



expresses the probability of its death, or the fraction of 

 the total number of animals which is dead at the time t. 

 If we multiply this probability b}^ 100, we obtain the per- 

 centage of dead tadpoles at the time t. 



The entire difference of order of death is explained 

 by this equation. Table 3 shows, on the basis of cal- 

 culated values, how the mortality and the order of 

 death vary when the number of cells whose inactivation 



TABLE 3 

 Mortality (number dying per minute) in a population of 100 

 multicellular organisms, calculated on the assumption that an individ- 

 ual dies when n of its cells are inactivated. 



500 



If 90% of the cells die per minute (the survival rate being 10%) 



If 80% of the cells die per minute (the survival rate being 20%) 



1st minute . 

 2nd minute. 

 3rd minute 

 4th minute. 

 5th minute 

 6th minute. 

 7th minute. 











1.80 

 43.13 

 40.42 

 11.50 



2.52 



If 70% of the cells die per minute (the survival rate being 30%) 



1st minute . 

 2nd minute. 

 3rd minute. 

 4th minute. 

 5th minute. 

 6th minute. 

 7th minute. 

 8th minute. 

 9th minute. 



70.00 

 21.00 

 6.30 

 1.89 

 0.56 

 0.17 

 0.05 

 0.02 

 0.01 



49.00 

 33.81 

 11.87 

 3.72 

 1.12 

 0.33 

 0.11 

 0.03 

 0.01 



16.81 

 45.60 

 24.79 

 8.82 

 2.77 

 0.84 

 0.26 

 0.08 

 0.02 



2.82 



36.12 



37.12 



16.13 



5.41 



1.67 



0.51 



0.16 



0.04 







0.90 



24.51 



41.19 



21.94 



7.87 



2.50 



0.77 



0.22 





 



6.48 



37.87 



34.05 



14.55 



4.87 



1.55 



0.43 















1.71 

 27.91 

 39.73 

 20.20 



7.28 



2.15 



