FORMULAS 283 



GROUP I. ALBINOS 



first division': formulas based on size 



Body Length on Body Weight, (Donaldson, '09) 



Body length {sexes combined) = 1^3 log (Bd. ivt. + 15) — 134 (4). 



A study of tables 1 and 2 in the investigations by Donaldson 

 ('09) shows that for a given body weight the body length of the 

 male is about 2.2 per cent greater than that of the female. If 

 then the value found by this formula for any body weight is 

 increased by 1.1 per cent of itself the sum obtained represents the 

 body length for the male. If on the contrary, the value found is 

 decreased by 1.1 per cent of itself, the difference obtained repre- 

 sents the body length for the corresponding female. 



Body Weight on Body Length (.Donaldson, '09) 



By transposing formula (4) we obtain 



Bcu.+m 

 Body weight {sexes combined) = 10 ^^^ - 15 (5) 



As the body length for a given body weight is for the male 1.1 

 per cent above the value in (5) and for the female 1.1 per cent 

 below the value in (5) two new formulas have been made for the 

 male and female respectively — thus 



( WdBd.l.-\ I Bd. 1) + 1M00 



Body weight:— ^nale = 10 " ^^oo - 15 (5a) 



(WOBd. l.+l.l Bd. Z.)+13400 



Body weight:— female = 10 i«oo _ 15 (5}-,) 



By use of formulas (5 a) and (5 b) the body weights corre- 

 sponding to body lengths from 70-250 mm. have been computed 

 for each sex and the values obtained are those entered in the 

 accompanying tables. 



To illustrate the procedure with a formula of this sort the 

 following example is given. 



To compute the body weight for a body length of 150 mm. 

 (male) by the following formula (5 a). 



jimBd.i.-i.iBd.i.+nwo) 

 Body weight {male) =10 14300 — 15 



