158 GROWTH OF PARTS AND ORGANS 



12. Formulas. Formulas for computing the length or weight 

 of the body and of its several parts, systems or organs, also for 

 expressing the values of other characters. 



The formulas for the Albino — Group I — are given first, then 

 those for the Norway — Group II. In Group I there are two 

 divisions. The first division comprises the formulas based on 

 size (body length and body weight). The second division com- 

 prises the formulas based on age. These formulas have been 

 kept simple in order to facilitate their use. This condition has 

 made it sometimes necessary to have different formulas for the 

 different parts of the same series of data, but this was deemed 

 more desirable than a reduction in the number of the formulas 

 at the price of greater complexity. 



After the formula there follows in parenthesis the number by 

 which it is designated in the text, and every formula, whether it 

 be general or subsidiary, is thus numbered, each subsidiary formula 

 carrying the number of the general formula to which it is related, 

 followed by a distinguishing letter. A catalog of the formulas, 

 given in detail later, is here presented. 



CATALOG OF FORMULAS 



GROUP I. ALBINOS 



First division: Formulas based on size 



Body length on body weight (J). 



Body weight on body length (2), (2 a), (2 b). 



Body weight on brain weight (3) . 



Tail length on body length (4), (5). 



Brain weight on body weight (6), (7). 



Cranial capacity on body weight (8), (9), (10). 



Spinal cord weight on body weight (11). 



Diameters of ganglion cell and nucleus (12), (12 a). 



Weight of both eyeballs on body weight (13). 



Weight of heart on body weight (14) . 



Weight of both kidneys on body weight (15). 



Weight of liver on body weight (16). 



Weight of spleen on body weight (17) . 



Weight of both lungs on body weight (18) . 



Volume of blood on body weight (19), (19 a), (19 b). 



Weight of blood on body weight (20), (20 a), (20 b). 



Weight of alimentary tract on body weight (21). 



