284 GROWTH OF PARTS AND ORGANS 



Transpose 15 from right hand side to the left and take the 

 logarithm of both sides. We have 



7 n^^ . , y^^ 7 in s/ (100 X 150 - 1.1 X 150) +13400 



log (Bd.wt. -\- 15) = log 10 X ^ 



14300 



, ,, 15000 - 165 + 13400 , ,,^,. 



'"^ r43oo =='-''^' 



Thus 1.9745 is equivalent to the logarithm of body weight plus 

 15. Therefore body weight + 15 = 94.3 (anti-logarithm 

 of 1.9745). Finally, body weight = 94.3 - 15 = 79.3 grams. 



The above procedure is that to be followed with other formulas 

 of the same type. 



Body Weight on Brain Weight (Donaldson, '08) 



Br. wl.-O.ooi 



Body weight {sexes combined) = 8.7+ 10 °-^^° (6) 



Tail Length on Body Length i,Hatai, ms '14) 



Tail length: male = 0.852 Ed. I + 38.8 {log Ed. I) - 90.5 (7) 

 Tail length:— female = 0.874 Ed. I + 43.2 {log Ed. I) - 98.1 (8) 

 Formulas (7) and (8) were used for table 144. 



Brain Weight on Body' Weight (Hatai, '09 a, p. 172) 



For the brain weight of sexes combined, the following form- 

 ulas have been obtained : — 



Brain weight {sexes combined) = 1.56 log {Ed. wt.) — 0.87 (9) 



[5 < Bd. wt. < 10 gms.] 



Brain weight {sexes combined) = 



0.569 log {Ed. ivt. - 8.7) +0.554 (10) 



Bd. wt. > 10 gms.] 



