hi] the PONDERAL index 199 



It is the rule in fishes and other cold-blooded vertebrates that 

 growth is asymptotic and size indeterminate, while in the warm- 

 blooded growth comes, sooner or later, to an end. But the 

 characteristic form is established earlier in the former case, and 

 changes less, save for the minor fluctuations we have spoken of. 

 In the higher animals, such as ourselves, the whole course of life 

 is attended by constant alteration and modification of form; and 



Fig. 52. The ponderal index, or weight-length coefficient, in 

 man. From Quetelet's data. 



we may use our weight-length formula, or ponderal index, to illus- 

 trate (for instance) the changing relation between height and weight 

 in boyhood, of which we spoke before (Fig. 52). 



regalis, Bull. U.S. Bureau of Fisheries, xxxni, pp. 141-147, 1913; Selig Hecht, 

 Form and growth in fishes, Journ. of Morphology, xxvii, pp. 379-400, 1916; 

 J. Johnstone (Plaice), Trans. Liverpool Biolog. Soc. xxv, pp. 186-224, 1911; 

 J. J. Tesch (Eel), Journ. du Conseil, iii, 1927; Frances N. Clark (Sardine), Calif. 

 Fish. Bulletin, No. 19, 1928 (with full bibliography). For a discussion on statistical 

 lines, apart from any assumptions such as the "law of the cubes," see G. Buncker, 

 Korrelation zwischen Lange u. Gewicht, etc., Wissensch. Meerestmtersuch. Helgoland, 

 XV, pp. 1-26, 1923. 



