304 Hubert P. Yockey 



Leslie and Ranson (36) fitted their data on the vole to a function of the 

 form of equation (9). They give a conventional yj- analysis to justify the 

 hypothesis. The y^ analysis cannot be applied to data obtained as these life 

 tables are obtained since the points are not statistically independent. The 

 random variable is the time of death of each animal, not the number alive at 



100 



FLIES (days) 

 25 35 42 50 55 60 65 70 74 78 62 



MICE (months) 



Fig. 3. Normal aging survivorship of certain strains of mice (52, 53) and Droso- 



phila melanogaster (35). Note that the abscissa is plotted as age squared to show 



that the dilute brown strain follows equation (9) but that others do not. 



a given interval of time. We are unable to justify our hypothesis in any objective 

 mathematical way. The standard errors given are calculated as follows where 

 /, is the number in the / interval and /j_,_i the number in the / + 1 interval 



(10 



The points in Fig. 2 lie very near to a straight line and so it is plausible, at 

 least, that equation (9) represents the normal aging survivorship for some 

 organisms. 



If the destruction of genetical information is the feature common to the 

 action of the deleterious agents discussed in this article then the survivorship 

 curve should be relatively insensitive to the character of the agent except 

 insofar as reflected by the fonn of J(A). That such is indeed the case is shown 



