Onset of Disease and Longevity of Rat and Man 77 



rats. These are identical with those in Fig. 3, except that the 

 time scale is here very much condensed. 



At the right-hand end of these charts are data on man — 

 plotted on the same time scale as the rat data. These data were 

 obtained by one of us (Dr. Davies) in 1945-46 while working 

 in this department. Examination was made of over 500 



100 

 80 



o 40 



o 



" 20 

 



RAT 



MAN 



,\hr. neph. 

 •^myo. degen. 



^^periarteritis 



PERCENT OF INDIVIDUALS 

 HAVING LESIONS 



10 



20 



30 



80 90 



AGE IN YEARS 



RAT At r 100 DAYS 



MAN At =10 YEARS 



40 - 



20 



^MUSC. DEGEN. 



XHR. NEPH. 

 PERIARTERITIS 

 rMYO. DEGEN. 



DISTRIBUTION OF 

 AGE OF ONSET 



HYPER. PR05T 



10 



AGE 



20 30 



YEARS 



COR. THROM. 



90 



Fig. 6. Data of rat and man plotted on the same age scale. 



Top Chart : Percentage of individuals having detectable lesions of diseases 



of their species. 

 Bottom chart : Age distribution of onset of lesions (probabiUty of onset). 



autopsy records of the Presbyterian Hospital. The data were 

 tabulated and some of the findings on males are reported here. 

 We recognize that such data are open to the criticism that the 

 autopsies were performed by numerous pathologists and that 

 the cases came from a very heterogeneous population. How- 

 ever, these objections apply equally to all the age groups 

 reported. Unfortunately, the number of cases in the upper 



