FORMULAS 293 



Body weight on age in days males = 



11.199 + 0.0475 Age + 0.0184 Age* (41) 



[10 < Age < 80] 

 = 488 log Age - 0.52 Age - 678.2 (42) 



[80 < Age < 365] 

 Body weight on age in days mated females = 



8.071 + 0.367 age + 0.0131 Age* (43) 



[10 < Age < 80] 

 = 343 log Age - 0.41 Age - 498.8 (44) 



[80 < Age < 365] 

 Formulas (41) (42) (43) (44) were used for table 157. 



WEIGHT OF THYMUS ON AGE (HATAI, '14) 



Weight of thymus sexes combined = 



0.01 X 10 ' (45) 



[Age < 95] 

 Weight of thymus = 



0.3903 - 0.00139 (age) + 0.00000128 (age)* (46) 



[Age > 95] 

 Formulas (45) (46) were used for table 151. 



PERCENTAGE OF WATER IN BRAIN (DONALDSON, '16) 



The formulas do not apply to rats under ten days of age. 

 Percentage of water in brain (male) = 



92.122 0.614 Age + 0.00739 Age* (Phase 1) (47) 

 [10 < Age < 40] 



