280 



GROWTH OF PARTS AND ORGANS 



TABLE 157 Concluded 



The first division -comprises the formula based on size (body 

 length and body weight). The second division comprises 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. 



