296 GROWTH OF PARTS AND ORGANS 



(1) For the male 



Body weight = 10- 0000629 (Bd ~ Lxm ~ [(m iooxaoo*]+ie) _ lg (54) 



_ I ^0.0000629 (Bd. J.X99.6+16500) _ -i o 



(2) For the female 



Body weight = 10- 0000629 (Bd - l -+ Bd - '.xiooxo.ooi+iesoo) _ lg (55) 



-| QO.OOOG629 (Bd. Z.X100.4+16500) _-o 



Formulas (54) (55) were used for table 187. 



TAIL LENGTH ON BODY LENGTH, NORWAY (HATAI, MS '14) 



(1) For the male 



Tail length = 0.824 Bd. I + 39.1 (log. Bd. Z.) - 92.6 (56) 



(2) For the female. 



Tail length = 0.824 Bd. I + 43.1 log (Bd. Z.) - 98.4 (57) 

 Formulas (56) (57) were used for table 187. 



BRAIN WEIGHT ON BODY WEIGHT, NORWAY (DONALDSON AND HATAI, '11) ' 

 Brain weight (sexes combined) 



= 0.825 log (Bd. wt. - 4) + 0.233 (58) 



This formula applies only to rats 5 grams or more in body 

 weight. To obtain the weights for the male the values given 

 by the formula are increased by 1 per cent, and to obtain the 

 weights for the female, they are decreased by 1 per cent. 



Formula (58) with corrections mentioned above was used for 

 table 187. 



CRANIAL CAPACITY ON BODY WEIGHT, NORWAY (DONALDSON, '12) 



Cranial capacity in cc. (sexes combined) = 



0.00105 Bd. wt. + 0.548 log Bd. wt. + 0.476 (59) 



[80 < Bd. wt. < 380] 



