i8 



EFFECT OF DIET ON THE ALBINO RAT 



of its life, while the omnivorous female had lived 41% of its life when 

 it had accomplished a similar part of its total work. A similar rela- 

 tion is seen to exist between the two sexes of the vegetarians. We also 

 see that the same fractional part of total work is accomplished at an 



Fractional part of total amount of 

 life's work 



O X 



W 



Males (3) . . 



Female ( i ) . 



Percentage of life re- 

 quired to do work. . 



Age in months re- 

 quired to do work. . 



Percentage of life re- 

 quired to do work. . 



Age in months re- 

 quired to do work. . 



.art 



bo'o 



>IL> 



w 



Male (i) 



Females (3) 



Percentage of life re- 

 quired to do work. . 



Age in months re- 

 quired to do work. . 



Percentage of life re- 

 quired to do work. . 



Age in months re- 

 quired to do work . . 



Vs 



M 



H 



/2 



Vs 



Va 



I6.I 



21.4 



32.1 



36.4 



46.4 



53-8 



4-5 



6. 



9- 



10.2 



13- 



15- 



19.1 



26.1 



32.3 



41. 



48.8 



53-8 



6.5 



8.9 



II. I 



13-8 



16.6 



19.9 



10. 



12.3 



17.6 



24.1 



32.8 



41.6 



2-3 



2.8 



4- 



5-5 



7-5 



9-5 



15-9 



22.5 



31-9 



42.5 



49- 



53-3 



2.7 



3-8 



54 



7.2 



8.3 



9.1 



67.9 



18. 



72.6 



24.7 

 517 



II.8 



66.1 

 1 1.2 



Table VI. — Comparison of omnivorous and 

 doing their life's work. 



vegetarian rats as to the rate of 



earlier age in the males than in the females of the same class, with the 

 exception of the last two items in the vegetarian group: here the male 

 is very slightly surpassed by the female. This shows that the male 

 ages earlier than the female. That is, when the male has begun to be 

 inactive the female of the same age is still quite active. 



We further see that the vegetarians do the bulk of their work at 

 an earlier age than the omnivorous rats. That is, they become old, 

 decrepit, lack energy and a desire to be active at an earlier age than 

 is true in the case of the omnivorous rats. This is true both as to per- 

 centage of life lived and age in months. For example, when the omni- 

 vorous rats had done seven-eighths of their total work the males had 

 lived 67.9% of their life and the females 72.6%, the two sexes averag- 

 ing 70%. In the case of the vegetarians the males had lived 51.7% 

 and the females 66.1%, or an average for the two sexes of 59%. We 

 thus see that the vegetarians had still an average of 41% of their lives 

 to live, during which time they did only one-eighth of their work. The 

 omnivorous had an average of 30% to live to do the remaining one- 

 eighth of their total work. 



