RATE OF PERFORMING ACTIVITY 



19 



We have already shown that the ratio of total average work done 

 by the omnivorous rats as compared to that of the vegetarians was 

 about as 7.5 : i. To make allowance for this, Table VII was construct- 

 ed. This shows the percentage of lifetime of the omnivorous rats and 

 their age in months which was required to do certain fractional parts 

 of the total work of the vegetarians. That is, the two groups are con- 

 sidered in respect to their ability to perform the same amount of work. 

 The data of the vegetarians is therefore the same in this table as in 

 Table VI. From this we see that the average ages in months of the 

 two classes correspond rather closely until three-eighths of their work 

 was done. After this the ages rapidly differ. When the vegetarian 

 male died it was 22.8 months old. The omnivorous male had accom- 

 plished the same amount of work when it was but 6.9 months old and 

 had lived but 22.5% of its life. The female vegetarian died at the 

 average age of 16.9 months. In contrast, the omnivorous female had 

 done the same amount of work at the age of 5.6 months, which was 

 equivalent to but 16.6% of its lifetime. Or the average total amount 

 of work of both sexes of vegetarians was performed at the average 

 age of 19.8 months, — ^that is, their average lifetime. Both sexes of the 

 omnivorous feeders had done the same work at the average age of 6.2 

 months, which was but 20.9% of their lifetime. 



Fractional part of total amount of 

 life's work 



Vs 



9.8 



2.7 



8.2 

 2.8 



10. 



2-3 



15-9 

 2.7 



13-8 

 3-8 



10.5 

 3-6 



12.3 

 2.8 



22.5 

 3.8 



14.6 



4- 

 10.9 



4- 

 17.6 



4- 



31-9 

 5-4 



157 

 4-3 



12.7 

 4-3 



24.1 

 5-5 



42.5 

 7.2 



18.3 



5- 

 13.6 



4.6 



32.8 

 7-5 



49. 

 8.3 



3/, 



20.5 

 5.6 



14.7 

 5- 



41.6 

 9-5 



53-3 

 9.1 



7/8 



22.5 

 6.2 



iS-7 

 5-3 



51-7 

 11.8 



66.1 

 11.2 



Vs 





Males (3) . . 



Percentage of life re- 

 quired to do work. . 



Age in months re- 

 quired to do work . . 



25.2 



6.9 





Female ( i ) . 



Percentage of life re- 

 quired to do work . . 



Age in months re- 

 quired to do work. . 



16.6 



5.6 



en 



Male (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. . 



100. 



22.8 





Females (3) 



100. 

 16.9 



Table VII. — Showing percentage of whole lifetime of omnivorous rats 

 required to accomplish the same work as that performed by the vegetarian rats 

 during the whole of their lifetime. 



